F 


APPLIED  TO 


AMB  MMBa<^ail^ 


BY  XAVIER  BICHAT, 

PHTSICIAN  or  THE  GREAT  HOSPITAL  OP  HFMAJflTT  AT  PARIS,  AND 
PROFESSOR  OF  ANAT03IT  AND  PHYSIOLOGX. 


CiranglateD  from  tfje  jFrenc!)» 


BY  GEORGE  HAYWARD,  M.  D. 

FELLOW  OF  THE  AMEHICAIf  ACADEUtT  OF  ARTS  AITD  SCIEHCE9, 
AJTD  OF  THE  SLASSACHOSETTS  MEDICAL  SOCIETT. 

t 


m THREE  VOLUMES. 
VOLUIUE  m. 


BOSTOJ^: 

PUBLISHED  BY  RICHARDSON  AND  LORD. 

J.  H.  A.  FROST,  PRINTER. 

1822. 


I 


DISTRICT  OP  MASSACHUSETTS,  to  wit  : 

District  Clerk’s  Office# 

BE  IT  REMEMBEtlED,  that  on  the  seventeenth  day  of  April,  A.  D.  1822,  in  the 
forty-sixth  year  of  the  Independence  of  the  United  States  of  America,  Richardson  <5*  Lord, 
of  the  said  District,  have  deposited  in  this  office  the  title  of  a book,  the  right  whereof  they 
clain^  as  proprietors,  in  the  words  following,  to  v}it  .• 

“ General  Anatomy,  applied  to  Physiolo^  and  Medicine ; by  Xavier  Bichat,  Physician 
of  the  Great  Hospital  of  Humanity  at  Paris,  aikl  Professor  of  Anatomy  and  Physiology. 
Translated  from  the  French,  by  George  Hayward,  M.  D.  Fellow  of  the  American  Acade- 
my of  Arts  and  Sciences,  and  of  the  Massachusetts  Medical  Society.  In  three  Volumes. 
Volume  III. 

In  couformity  to  the  Act  of  the  Congress  of  the  United  States,  entitled,  ‘‘  An  Act  for  the 
Encouragement  of  Learning,  by  securing  the  Copies  of  Maps,  Charts  and  Books,  to  the 
Authors  and  Proprietors  of  such  Copies,  during  the  times  therein  mentioned  and  also  to 
an  Act  entitled,  “ An  Act  supplementary  to  an  Act,  entitled.  An  Act  for  the  encouragement 
of  Learning,  by  securing  the  Copies  of  Maps,  Charts  and  Books,  to  the  Authors  and  Pro- 
prietors of  such  Copies  during  the  times  therein  mentioned;  and  extending  the  Benefits 
thereof  to  the  Arts  of  Designing,  Engraving  and  Etching  Historical  and  other  Prints.” 

JOHN  W.  DAVIS, 

Clerk  of  the  District  of  Massachusetts. 


MUSCULAR  SYSTEM  OF  ORGANIC 
LIFE. 


THIS  system  Is  not  as  abundantly  spread  out  in  the 
economy  as  the  preceding.  The  whole  mass  which  it 
forms,  compared  with  the  whole  of  the  other,  which  is 
more  than  one  third  of  the  body,  presents  in  this  respect 
a very  remarkable  difference.  Its  position  is  also  differ- 
ent; it  is  concentrated,  1st,  in  the  thorax,  where  the 
heart  and  oesophagus  belong  to  it ; 2d,  in  the  abdomen 
where  the  stomach  and  intestines  are  in  part  formed  by 
it ; 3d,  in  the  pelvis  where  it  contributes  to  form  the 
bladder  and  even  the  womb,  though  this  belo’ngs  to  gen- 
eration, which  is  a function  distinct  from  organic  life. 
This  system  then  occupies  the  middle  of  the  trunk,  is 
foreign  to  the  extremities,  and  is  found  far  from  the 
action  of  external  bodies,  whilst  the  other  superficially 
situated,  forming  almost  alone  the  extremities,  seems,  as 
we  have  said,  almost  as  much  destined  in  the  trunk  to 
protect  the  other  organs,  as  to  execute  the  different  mo- 
tions of  the  animal.  The  head  contains  no  part  of  the 
organic  muscular  system  ; this  region  of  the  body  is 
wholly  devoted  to  the  organs  of  animal  life. 


4 


MUSCULAR  SYSTEM 


ARTICLE  FIRST. 

OP  THK  PORMS  OF  THE  MUSCULAR  SYSTEM  OP  ORGANIC 

LIFE. 

All  the  muscles  of  the  preceding  system  take  in  gen- 
eral a straight  direction.  These  are  all  on  the  contrary 
curved  upon  themselves  ; all  represent  muscular  cavities 
differently  turned,  sometimes  cylindrical  as  in  the  intes- 
tines, sometimes  conical  as  in  the  heart,  sometimes  round- 
ed as  in  the  bladder,  and  sometimes  very  irregular  as  in  the 
stomach.  No  one  is  attached  to  the  bones  ; all  are  desti- 
tute of  tendinous  fibres.  The  white  fibres  arising  from 
the  internal  surface  of  the  heart,  and  going  to  be  attached 
to  tlie  valves  of  its  ventricles,  have  by  no  means  the 
nature  of  the  tendons.  Ebullition  does  not  easily  reduce 
them  to  gelatine ; desiccation  does  not  give  them  the 
yellowish  appearance  of  these  organs  ; they  resist  macer- 
ation longer  than  them. 

It  is  in  general  a great  character  that  distinguishes  the 
muscular  organic  system  from  that  of  animal  life,  that  it 
docs  not  arise  from,  nor  terminate  in  fibrous  organs.  All 
the  fibres  of  this  last  are  continuous  either  with  tendons, 
or  aponeuroses  or  fibrous  membranes.  Almost  all  those 
of  the  first  go  on  the  contrary  from  the  cellular  texture, 
and  return  to  it  after  having  run  their  course.  I at  first 
thought  that  the  dense  and  compact  texture  which  is  be- 
tween the  mucous  membrane  and  the  fleshy  fibres  of  the 
intestines,  the  bladder,  the  stomach,  &c.  was  an  assem- 
blage and  net-work  of  many  small  tendons  corresponding 
to  these  fibres,  and  interwoven  in  the  form  of  an  aponeu- 
rosis ; the  density  of  this  layer  deceived  me  at  first  view. 
Ebullition,  maceration,  and  desiccation  have  since  taught 
me,  that  this  layer,  completely  foreign  to  the  fibrous  sys- 
l.eiUj  should  be  referred,  as  Haller  has  said,  to  the  cellular, 


OF  ORGANIC  LIFE. 


which  is  only  more  dense  and  compact  there  than  else- 
where. It  is  this  layer,  which  I have  designated,  in  the 
cellular  system  by  the  name  of  the  sub-mucous  texture. 
Many  fibres  of  the  system  of  which  we  are  treating  ap- 
pear to  form  an  entire  curve,  which  is  not  crossed  by 
any  cellular  intersection ; some  layers  of  the  heart  ex- 
hibit this  arrangement,  which  is  in  general  very  rare ; so 
that  there  is  almost  always  an  origin  and  termination  df 
the  fibres,  upon  an  organ  of  a nature  difierent  from  their 
own. 

We  can  hardly  consider  in  a general  manner  the  forms 
of  the  system  of  which  we  are  treating  ; each  organ  be- 
longing to  it  is  moulded  upon  the  form  of  the  viscus  to 
the  formation  of  which  it  contributes.  In  fact,  the  or- 
ganic muscles  do  not  exist  in  distinct  fasciculi,  like  those 
of  animal  life  ; all,  except  the  heart,  form  but  a third,  a 
quarter  and  often  even  less  in  the  structure  of  a viscus. 

The  gi'eatest  number  has  a thin,  flat  and  membranous 
form.  There  are  layers  more  or  less  broad,  and  hardly 
ever  distinct  fasciculi.  Placed  at  the  side  of  each  other, 
the  fibres  are  rarely  one  above  another ; hence  it  happens 
that  occupying  a very  great  extent,  these  muscles  form 
however  a very  small  volume.  The  great  gluteus  alone 
would  be  larger  than  all  the  fibres  of  the  stomach,  the  in- 
testines and  the  bladder,  if  they  Avere  united  like  it  into 
a thick  and  square  muscle. 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC 

LIFE. 

The  organization  of  the  involuntary  muscles  is  not  as 
uniform  as  that  of  the  preceding.  In  these  all  is  exactly 


6 


MUSCULAR  SYSTEM 


similar  excepting  the  differences  of  the  proportion  of  tlie 
fleshy  fibres  to  the  tendinous,  of  the  length  of  the  first, 
of  the  prominence  of  the  fasciculi,  of  their  assemblage 
into  flat,  long  or  short  muscles ; in  whatever  place  we  ex- 
amine them,  their  varieties  are  in  their  forms  and  not  in 
their  texture.  Here  on  the  contrary,  there  is  in  this  tex- 
ture marked  differences ; the  heart  compared  with  the 
stomach,  the  intestines  with  the  bladder  are  sufficient  to 
convince  us  of  this.  It  is  by  virtue  of  these  different 
textures,  that  the  contractility  and  sensibility  vary  as  we 
shall  see  in  each  muscle,  that  the  force  of  the  contraction 
is  not  the  same,  and  that  life  is  difi’erent  in  each,  whilst  it 
is  uniform  in  all  those  of  animal  life.  We  shall  now 
consider  in  a general  manner  the  organization  of  the  in- 
voluntary muscles. 

I.  Texture  peculiar  to  the  Organization  of  the  Mus- 
cular System  of  Organic  Life. 

The  organic  muscular  fibre  is  in  general  much  finer  and 
more  delicate  than  that  of  the  preceding  system  ; it  is 
not  brought  into  as  thick  fasciculi.  Very  red  in  the 
heart,  it  is  whitish  in  the  gastric  and  urinary  organs. 
Besides,  this  colour  varies  remarkabl}^.  I have  observed 
that  sometimes  maceration  renders  it  of  a deep  brown  in 
the  intestines. 

This  fibre  never  has  one  single  direction,  like  that  of 
the  preceding  muscles ; it  is  interlaced  always,  or  found 
in  juxta-position  in  different  directions  ; sometimes  it  is  at 
a right  angle  that  the  fasciculi  are  cut,  as  in  the  longi- 
tudinal and  circular  fibres  of  the  gastric  tubes ; sometimes 
it  is  with  angles  more  or  less  obtuse  or  acute,  as  in  the 
stomach,  the  bladder,  &c.  In  the  heart,  this  interlacing  is 
such  in  the  ventricles,  that  it  is  a true  muscular  net-work. 
From  these  varieties  of  direction,  results  an  advantage  in 
the  motions  of  these  sorts  of  muscles,  which,  being  all 


OF  ORGANIC  LIFE. 


hollow  can  by  contracting  diminish  according  to  many 
^ diameters  the  extent  of  their  cavity. 

Every  organic  muscular  fibre  is  in  general  short ; those 
which,  like  the  longitudinal  of  the  oesophagus,  the  rectum, 
&c.  appear  to  run  a long  course,  are  not  continuous ; they 
arise  and  terminate  at  short  distances,  and  thus  arise  and 
terminate  successively  in  the  same  direction  or  line ; no 
one  is  comparable  to  those  of  the  sartorius,  the  gracilis, 
&c.  as  it  respects  length. 

We  know  the  nature  of  their  fibres  no  better  than  that 
of  those  of  animal  life  ; but  they  appear  nearly  the  same 
under  the  action  of  the  different  reagents.  Desiccation, 
putrefaction,  maceration,  ebullition,  exhibit  in  them  the 
same  phenomena.  I have  observed  upon  the  subject  of 
this  last,  that  once  boiled,  the  fibres  of  both  systems  are 
much  less  alterable  by  the  acids  sufficiently  weakened. 
After  being  some  time  in  the  sulphuric,  the  muriatic  and 
nitric  diluted  with  water,  they  soften  a little,  but  keep 
their  orignal  form,  and  do  not  change  into  that  pulp  to 
which  raw  fibres  are  always  reduced  in  the  same  experi- 
ment. The  last  of  these  acids  turns  them  yellow  as  be- 
fore ebullition. 

I have  also  made  an  observation  as  it  respects  the  horny 
hardening  which  is  produced  the  instant  ebullition  com- 
mences ; it  is  this,  that  it  is  always  the  same  whatever 
may  have  been  the  antecedent  dilatation  or  contraction  of 
the  fibres.  The  stomach  which  at  death  was  so  dilated  as 
to  contain  many  pints  of  fluid,  is  reduced  to  the  same 
size,  all  other  things  being  equal,  as  that  which  is  con- 
tracted so  as  to  be  no  larger  than  the  coecum.  Diseases 
have  a little  influence  on  the  horny  hardening.  The  heart 
of  a phthisical  patient  exhibited  to  me  in  the  same  expe- 
riment this  phenomenon  much  less  evidently,  than  that 
of  an  apoplectic. 

The  resistance  of  the  organic  muscular  fibre  is  in  pro- 
portion much  greater  than  that  of  the  fibres  of  the  animal 


s 


MUSCULAR  SYSTEM 


muscular  system.  Whatever  may  be  the  distension  of  the 
hollow  muscles  by  the  fluid  which  fills  them  during  life? 
ruptures  hardly  ever  take  place  in  them. 

The  bladder  alone  sometimes  exhibits  this  phenome- 
non, which  is  however  very  rare  in  it.  In  the  great 
retentions  of  the  urine,  in  which  ruptures  take  place,  it  is 
almost  always  the  urethra  that  is  ruptured,  and  the  blad- 
der remains  whole.  We  meet  in  practice  with  a hundred 
fistulas  in  the  perineum,  coming  from  the  membranous 
portion,  to  one  above  the  pubis.  We  find  in  authors  many 
examples  of  rupture  of  the  diaphragm  ; we  know  of  but  few 
of  the  rupture  of  the  stomach,  the  intestines  and  the  heart. 

II.  Common  Parts  in  the  Organization  of  the  Muscu- 
lar System  of  Organic  Life. 

The  cellular  texture  is  in  general  much  more  rare  in 
the  organic  muscles  than  in  the  others.  The  fibres  of  the 
heart  are  in  juxta-position,  rather  than  united  by  this  tex- 
ture. It  is  a little  more  evident  in  the  gastric  and  urinary 
muscles.  It  is  almost  wanting  in  the  womb ; thus  these 
muscles  are  not  infiltrated,  like  the  preceding,  in  dropsies  ; 
they  never  exhibit  that  fatty  state  of  which  we  have 
spoken,  and  which  sometimes  loads  the  fibres.  I have  not 
observed  in  these  fibres  the  yellowish  tinge  which  the 
others  often  take,  especially  in  the  vertebral  depressions. 

The  blood  vessels  are  very  numerous  in  this  system  ; 
they  are  found  in  it  even  in  greater  proportion  than  in  the 
other ; more  blood  consequently  penetrates  them.  This 
fact  is  remarkable,  especially  in  the  intestines,  in  which 
the  mesenteric  arteries  distribute  numerous  branches,  over 
an  extremely  delicate  fleshy  surface.  But  I would  remark 
that  this  appearance  is  to  a certain  degree  deceptive,  as 
many  of  these  vessels,  only  traverse  the  fleshy  surface  to 
go  to  the  mucous  membrane.  In  the  ordinary  state  they 
give  to  the  gastric  viscera  a reddish  tinge,  which  I have 
rendered  at  will  livid  and  afterwards  brought  back  to  its 


OF  ORGANIC  LIFE. 


9 


primitive  state,  by  shutting  and  afterwards  opening  the 
stop-cock  adapted  to  the  wind  pipe,  in  my  experiments 
upon  asphyxia. 

The  absorbents  and  exhalants  have  nothing  peculiar  in 
this  system. 

The  nerves  come  to  them  from  two  sources ; 1st,  from 
the  cerebral  system  ; 2d,  from  that  of  the  ganglions. 

Except  in  the  stomach  in  which  the  par  vagum  is  dis- 
tributed, the  nerves  of  the  ganglions  predominate  every- 
where. In  the  heart,  they  are  the  principal ; in  the  intes- 
tines, they  are  the  only  ones ; at  the  extremity  of  the 
rectum  and  the  bladder,  their  proportion  is  greater  than 
that  of  the  nerves  coming  from  the  spine. 

The  cerebral  nerves  intermix  with  them,  in  penetrating 
the  organic  muscles.  The  cardiac,  solar,  hypogastric, 
plexuses,  &c.  result  from  this  intermixture  which  appears 
to  have  an  influence  upon  the  motions,  though  we  are 
ignorant  of  the  nature  of  this  influence. 

All  the  nerves  of  the  ganglions  which  go  to  the  organic 
muscles,  do  not  appear  to  be  exclusively  destined  to  them. 
A great  number  of  filaments  belong  only  to  the  arteries ; 
such  is  in  fact  their  interlacing,  that  they  form,  as  we 
have  seen,  around  these  vessels  a real  nervous  membrane, 
superadded  to  their  own,  and  exclusively  destined  to 
them.  I would  compare  this  nervous  envelope  to  the 
cellular  envelope  which  is  also  found  around  the  arteries, 
and  which  is  wholly  distinct  from  the  surrounding  cellu- 
lar texture  ; thus  it  only  has  communications  with  the 
nerves  of  the  organic  muscles,  without  being  distributed 
to  these  muscles.  Besides  as  the  nerves  of  the  ganglions 
are  always  the  most  numerous  and  essential  in  them,  and 
as  their  tenuity  is  extreme,  the  nervous  mass  destined  to 
each  is  infinitely  inferior  to  that  which  is  found  in  the 
voluntary  muscles.  The  heart  and  the  deltoid  muscle 
compared  together,  exhibit  in  this  respect  a remarkable 
difference. 

o 


VOL.  III. 


10 


MUSCULAR  SYSTEM 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC  LIFE. 


Under  the  relation  of  properties,  this  system  is  in  part 
analogous  to  the  preceding,  and  in  part  very  different 
from  it. 

I.  Properties  of  Texture.  Extensibility. 

Extensibility  is  very  evident  in  the  organic  muscles. 
The  dilatation  of  the  intestines  and  the  stomach  by  ali- 
ments, by  the  extrication  of  gas,  by  the  fluids  that  are 
found  there,  that  of  the  bladder  by  the  urinfe,  by  injec- 
tions that  are  forced  in,  &c.  are  essentially  owing  to  this 
extensibility. 

This  property  is  characterized  here  by  two  remarkable 
attributes  ; 1st,  by  the  rapidity  with  which  it  can  be  put 
into  action  ; 2d,  by  the  very  great  extent  of  which  it  is 
susceptible. 

The  stomach  and  intestines  pass  in  an  instant  from  com- 
plete vacuity  to  great  extension.  Artificially  distended, 
tlie  bladder  becomes  immediately  of  a size  treble,  qua- 
druple even  of  that  which  is  natural  to  it.  It  sometimes 
however  resists,  but  this  does  not  prove  its  defect  of  ex- 
tensibility ; it  is  because  the  fluid  injected  irritates  it  and 
makes  it  contract ; the  organic  contractility  in  exercise, 
then  prevents  the  development  of  extensibility,  as  it  some- 
times cannot  be  brought  into  action  by  stimulants  in  a 
muscle  laid  bare,  because  the  animal  contractility  in  exer- 
cise in  the  muscle,  forms  an  obstacle  to  it.  The  muscles 
of  animal  life  are  never  capable  of  this  rapidity  in  their 


OF  ORGANIC  LIFE. 


11 


extensibility,  whether  because  they  are  intersected  by 
numerous  aponeuroses  which  dilate  hut  slowly,  or  whether 
because  their  layers  of  fibres  are  very  thick,  two  circum- 
stances that  do  not  exist  in  the  muscles  of  organic  life. 
Hence  a remarkable  phenomenon  that  I have  observed  in 
all  cases  of  tympanites.  When  we  open  the  abdomen  of 
subjects  that  have  died  in  this  state,  without  wounding 
the  swelled  intestines,  these  immediately  burst  out,  swell 
more,  and  occupy  twice  as  large  a space  as  they  were 
contained  in  in  the  .abdomen  ; why  ? Because  the  parietes 
of  the  abdomen  being  unable  to  yield  in  proportion  to  the 
quantity  of  gas  that  is  developed,  this  has  been  com- 
pressed in  the  intestines  during  life,  and  expands  imme- 
diately by  its  elasticity  when  the  cause  of  compression 
ceases.  In  dropsies  in  which  the  distension  is  slow,  the 
abdominal  parietes  enlarge  much  more  than  in  tympanites. 
The  size  of  the  abdomen  would  be  double  in  this,  if  the 
extensibility  of  the  parietes  was  in  proportion  to  that  of 
the  intestines. 

As  to  the  extent  of  the  extensibility  of  the  organic  mus- 
cles, we  can  form  an  idea  of  it  by  comparing  the  empty 
stomach  which  oftentimes  is  not  larger  than  the  caecum 
in  its  or^nary  state,  with  the  stomach  containing  some- 
times five,  six  and  even  eight  pints  of  fluid  ; the  bladder 
contracted  and  concealed  behind  the  pubis,  with  the  blad- 
der full  of  urine  from  suppression,  rising  sometimes  even 
above  the  umbilicus  ; the  rectum  empty,  with  the  rectum 
filling  a part  of  the  pelvis  in  old  people  in  whom  the 
excrements  have  accumulated  in  it ; the  intestines  con- 
tracted with  the  intestines  greatly  distended. 

It  is  to  the  extent  of  extensibility  of  the  organic  mus- 
cles and  to  the  limits  placed  to  that  of  the  abdominal 
parietes,  that  must  be  referred  a constant  phenomenon 
that  is  observed  in  the  gastric  viscera  ; viz.  that  in  the 
natural  series  of  their  functions,  they  are  never  all  dis- 
tended at  the  same  time ; the  intestines  are  filled  when 


12 


MUSCULAR  SYSTEM 


the  matters  contained  in  the  stomacli  are  evacuated ; the 
bladder  is  not  full  of  urine  in  the  digestive  order,  until 
the  other  hollow  organs  are  empty,  &.c.  In  general,  that 
is  an  unnatural  order  in  which  all  the  organs  are  dis- 
tended at  once. 

There  is  for  the  organic  muscles  a mode  of  extensibility 
wholly  different  fi-om  that  of  which  I have  just  spoken  ; 
it  is  that  of  the  heart  in  aneurisms,  and  the  womb 
in  pregnancy.  The  first,  for  example,  acquires  a size 
double,  treble  even  sometimes  in  its  left  side,  and  yet  it 
increases  at  the  same  time  in  thickness.  This  size  is  not 
owing  to  distension,  but  to  a preternatural  growth.  The 
aneurismatic  heart  is  to  the  ordinary  heart,  what  this  is  to 
the  heart  of  the  infant ; it  is  nutrition  that  makes  the 
difference  and  not  distension  ; for  whenever  it  is  owing 
to  this  it  diminishes  in  thickness  as  it  increases  in  extent; 
there  is  no  addition  of  substance.  Besides  the  aneuris- 
matic heart  has  not  often  the  cause  that  distends  it,  for 
commonly  in  this  case  the  mitral  valves  allow  a free 
passage  to  the  blood  ; whilst  when  they  are  ossified  the 
left  ventricle  often  remains  in  a natural  state.  Moreover, 
the  slow  progress  of  the  formation  of  aneurism  proves 
that  it  is  a preternatural  nutrition  that  has  presided  over 
this  increase  of  the  heart.  You  would  in  vain  then  empty 
this  organ  of  the  blood  it  contains,  it  would  not  contract 
and  resume  its  dimensions,  as  the  inflated  intestine  does 
which  we  puncture  to  allow  the  air  to  escape. 

In  the  womb  there  are  two  causes  of  distension;  1st, 
the  sinuses  greatly  developed  ; 2d,  an  addition  of  sub- 
stance, a real  momentary  increase  of  the  fibres  of  the 
organ  which  remains  as  thick  and  even  more  so  than  in 
the  natural  state.  At  the  time  of  accouchement,  the 
sinuses  immediately  flatten  by  the  contraction  of  the 
fibres  ; hence  the  sudden  contraction  of  the  organ.  But 
as  on  the  one  hand  nutrition  alone  can  remove  by  de- 
composition the  substances  added  to  the  fibres  to  enlarge 


OF  ORGANIC  LIFE. 


13 


them,  and  as  on  the  other,  this  function  is  exerted  slowly, 
after  the  womb  has  undergone  the  sudden  contraction 
owing  to  the  flattening  of  its  sinuses,  it  returns  but  gra- 
dually and  at  the  end  of  some  time  to  its  ordinary  size. 
Extensibility  is  not  then  brought  into  action  in  the  womb 
filled  by  the  foetus,  and  in  the  aneurismatic  heart ; these 
organs  really  become  at  that  time  the  seat  of  a more 
active  nutrition  ; they  grow  preternaturally,  as  they  have 
grown  naturally  with  the  other  organs  ; but  these  do  not 
then  experience  an  analogous  phenomenon,  they  become 
monstrous  in  comparison.  The  womb  decreases,  because 
the  motion  of  decomposition  naturally  predominates  over 
that  of  composition  after  accouchement,  whilst  it  was  the 
reverse  before  this  period.  The  aneurismatic  heart  re- 
mains always  so. 

These  dilatations  of  the  heart  should  be  carefully  dis- 
tinguished from  those  really  produced  by  extensibility, 
as  in  the  right  auricle  and  ventricle  for  example,  which 
are  found  full  of  blood  at  the  moment  of  death,  because 
the  lungs  which  are  weakened,  not  allowing  it  to  pass 
through  them,  compel  it  to  flow  back  to  the  place  from 
which  it  came.  There  are  but  few  hearts  which  do  not 
exhibit  in  very  various  degrees,  these  dilatations,  which 
we  have  the  power  in  a living  animal  of  increasing  or 
diminishing  at  will,  according  to  the  kind  of  death  we 
produce.  Two  hearts  are  hardly  ever  of  the  same  size 
after  death  ; many  varieties  are  met  with,  and  these  de- 
pend more  or  less  on  the  difliculties  which  the  blood  ex- 
periences in  the  last  moments,  in  passing  through  the 
lungs.  Hence  why  in  the  diseases  of  the  heart,  there  is 
no  standard  by  which  we  can  compare  the  morbid  size, 
especially  if  we  examine  the  organ  as  a whole.  In  fact 
the  distension  of  the  right  side  can  give  it  an  aneurismatic 
appearance,  and  a size  even  greater  than  that  of  some 
aneurisms.  If  we  examine  the  left  side  separately,  the 
error  is  more  easily  proved,  because  this  side  is  subject 


14 


MUSCULAR  SYSTEM 


to  less  variations.  But  the  principal  difierence  consists 
in  the  thickness.  The  power  of  contraction  appears  to 
increase  in  proportion  to  tliis  thickness,  which  arises 
from  the  substance  added  by  nutrition.  It  is  this  power 
whicli  produces  tlie  «Teat  beating  that  is  felt  under  the 
ribs,  the  strength  of  the  pulse,  &c. 

Contractility . 

It  is  in  proportion  to  extensibility.  It  is  often  brought 
into  action  in  the  ordinary  state.  It  is  in  virtue  of  this 
property,  that  the  stomach,  the  bladder,  the  intestines, 
&c.  contract,  and  acquire  a size  so  small  compared  to 
what  they  have  when  they  are  full.  In  general,  there  is 
no  muscle  of  animal  life,  which  is  capable  of  such  ex- 
treme contractions  as  those  of  organic  life. 

It  should  be  remarked,  however,  that  life,  without 
having  contractility  immediately  dependant  upon  it,  since 
the  intestines,  the  stomach,  and  the  bladder  contract  after 
death  when  their  distension  is  removed,  modifies  it  in  a 
very  evident  manner.  The  causes  even  which  alter  or 
diminish  the  vital  forces  have  an  influence  upon  it ; hence 
the  following  observation  that  all  those  accustomed  to 
open  dead  bodies  can  make.  When  the  subject  has  died 
suddenly,  and  the  stomach  is  empty,  it  is  much  contract- 
ed ; when,  on  the  contrary,  death  has  been  preceded  by 
a long  disease  which  has  weakened  its  forces,  the  stomach, 
though  empty,  remains  flaccid,  and  is  found  but  very 
little  contracted. 

We  should  consider  the  substances  contained  in  the 
hollow  muscles  of  organic  life,  as  true  antagonists  of 
these  muscles  ; for  they  have  not  muscles  that  act  in  a 
direction  opposite  to  theirs.  As  long  as  these  antagonists 
distend  them,  they  do  not  obey  their  contractility  of  tex- 
ture ; when  they  are  empty,  this  is  brought  into  action. 
It  is  not,  however,  upon  this  property  that  the  mechanism 
of  the  expulsion  of  matters  from  these  organs  turns,  as 


OF  ORGANIC  LIFE. 


15 


aliments  from  the  stomach  and  intestines,  urine  from  the 
bladder,  blood  from  the  heart,  &c.  It  is  the  organic  con- 
tractility that  presides  over  this  mechanism.  It  is  diffi- 
cult to  distinguish  these  properties  in  exercise.  One  oc- 
casions a slow  and  gradual  contraction,  which  is  without 
the  alternation  of  relaxation  ; the  other,  quick  and  sud- 
den, consisting  in  a series  of  relaxations  and  contractions, 
produces  the  peristaltic  motion,  those  of  systole,  diastole, 
&c.  It  is  after  the  organic  contractility  has  procured 
the  evacuation  of  the  hollow  muscles,  that  the  contrac- 
tility of  texture  closes  them.  In  death  from  hemorrhage 
from  a great  | artery,  the  left  and  even  the  right  side  of 
the  heart  send  out  all  the  blood  they  contain  ; afterwards 
empty,  they  contract  powerfully,  and  the  organ  is  very 
small.  On  the  contrary,  it  is  very  large  when  much 
blood  remaining  in  its  cavities,  distends  it,  as  in  asphyxia. 
These  are  the  two  extremes.  There  are,  as  I have  said, 
many  intermediate  states. 

The  contractility  of  texture  is,  in  the  system  of  which 
we  are  treating,  in  proportion  to  the  number  of  fleshy 
fibres.  Thus,  all  things  being  equal,  the  rectum,  when 
empty,  contracts  upon  itself  with  much  more  force  than 
the  other  large  intestines  ; the  contraction  of  the  ventri- 
cles is  much  greater  than  that  of  the  auricles,  and  that  of 
the  oesophagus  is  much  greater  than  that  of  the  duode- 
num, &c.  &c. 


II.  Vital  Properties. 

They  are  almost  in  an  inverse  order  of  those  of  the 
preceding  system. 

Properties  of  Jinimal  Life.  Sensibility. 

The  animal  sensibility  is  slight  in  the  organic  muscles. 
We  know  the  observation  related  by  Harvey  upon  a 
caries  of  the  sternum  that  laid  bare  the  heart ; they  irri- 


16 


MUSCULAR  SYSTEM 


tated,  without  its  being  felt  by  the  patient,  this  organ, 
which  only  contracted  under  the  stimulant.  Remove  the 
peritoneum  behind  the  bladder  of  a living  dog,  and  irri- 
tate the  subjacent  muscular  layer,  the  animal  gives  but 
few  marks  of  pain.  It  is  difficult  to  make  these  experi- 
ments upon  the  intestines  and  the  stomach  ; their  muscu- 
lar coat  is  so  delicate  that  we  cannot  act  upon  it  without 
at  the  same  time  stimulating  the  subjacent  nerves. 

It  appears  that  the  organic  muscles  are  much  less  sus- 
ceptible of  the  feeling  of  lassitude,  of  which  the  preceding 
become  tbe  seat  after  great  exercise.  I do  not  know 
however  if  in  those  to  which  mahy  cerebral  nerves  go, 
it  does  not  take  place ; for  example,  when  tbe  stomach 
has  been  for  a long  time  contracted,  it  is  probable  that  the 
lassitude  of  its  fibres,  produces  in  part  the  painful  sensa- 
tion that  we  then  have,  and  which  we  call  hunger,  a sen- 
sation that  should  be  distinguished  from  the  general  affec- 
tion that  succeeds  it,  and  which  becomes  truly  a disease, 
when  abstinence  has  been  too  much  prolonged.  We 
know  that  substances  not  nutritive  then  appease  this  sen- 
sation without  remedying  the  disease,  when  the  stomach 
is  filled  with  them.  I refer  to  the  same  kind  of  sensi- 
bility the  anxiety  and  distress  which  patients  experience, 
in  whom  we  keep  the  bladder  in  permanent  contraction 
by  an  open  sound  in  the  urethra,  which  transmits  the 
urine  as  fast  as  it  falls  from  the  ureters.  This  sensation 
does  not  resemble  that  of  hunger,  because  the  sensibility 
of  the  bladder  and  that  of  the  stomach  being  different, 
their  modifications  cannot  be  the  same.  Thus  each  of 
these  two  sensations  is  different  from  that  of  which  the 
muscles  of  animal  life,  for  a long  time  contracted,  become 
the  seat.  I do  not  believe  that  the  sensation  of  huna-er 

O 

belongs  solely  to  the  cause  I have  pointed  out,  and  which 
others  have  not  spoken  of ; but  it  cannot  be  denied  that 
it  has  much  part  in  it.  Who  knows  if,  after  a fever  in 
which  the  action  of  the  heart  has  been  for  a long  time 


OF  ORGANIC  LIFE. 


17 


accelerated,  the  weakness  of  the  pulse  which  accompanies 
convalescence,  is  not  a sign  of  the  lassitude  in  which  its 
fleshy  fibres  are,  on  account  of  the  antecedent  motion? 
We  know  the  painful  sensation  of  fatigue  which  the 
stomach  experiences  after  the  contractions  of  vomiting. 

Contractility . 

The  animal  contractility  is  foreign  to  the  muscles  of 
organic  life.  To  be  convinced  of  this,  we  must  recollect 
that  on  the  one  hand  this  contractility  alwa5^s  supposes 
the  influence  of  the  brain  and  the  nerves,  to  bring  in 
play  the  action  of  the  muscle,  and  that  on  the  other,  the 
brain,  in  order  to  exert  this  influence,  must  be  excited  by 
the  will,  by  stimulants  or  by  sympathies.  Now  none  of 
these  causes  acting  upon  the  brain,  the  organic  muscles 
cannot  contract. 

Every  body  knows  that  these  muscles  are  essentially 
involuntary.  If  some  men  have  had  the  faculty  of  arrest- 
ing the  motions  of  the  heart,  it  is  not  upon  this  organ  that 
the  brain  has  acted  ; the  action  of  the  diaphragm  and  the 
intercostals  has  first  been  suspended  ; respiration  has 
ceased  for  a time  ; then  consequently  the  circulation. 

If  we  irritate  the  brain  with  a scalpel  or  any  other 
stimulant,  the  muscles  of  animal  life  become  convulsed ; 
they  are  paralyzed  if  we  compress  this  organ.  Those  of 
organic  life,  on  the  contrary  preserve  in  both  cases  their 
natural  degree  of  motion.  The  heart  still  continues  to 
beat,  the  intestines  and  stomach  move  some  time  after  the 
cerebral  mass  and  spinal  marrow  have  been  taken  away. 
Who  does  not  know  that  the  circulation  goes  on  very 
well  in  acephalous  foetuses ; that  after  the  blow  that  has 
knocked  down  an  animal,  and  rendered  his  whole  volun- 
tary muscular  system  immoveable,  the  heart  is  still  for  a 
long  time  agitated,  the  bladder  rejects  the  urine,  the  rec- 
tum expels  the  excrements,  &c.  the  stomach  even  some- 
times vomits  up  aliments  ? Opium,  which  benumbs  the 
VOL.  ITT.  3 


18 


MUSCULAR  SYSTEM 


whole  animal  life,  because  it  acts  especially  upon  the  brain 
which  is  the  centre  of  it,  which  paralyzes  all  the  volun- 
tary muscles,  leaves  the  others  unaffected  in  their  contrac- 
tions. Intoxication  produced  by  wine  exhibits  the  same 
phenomenon.  A man  staggers  after  drinking  ; his  limbs 
refuse  to  carry  him,  and  yet  his  heart  beats  with  force  ; 
his  stomach  often  heaves  and  rejects  the  surplus  fluids  it 
contains.  All  narcotic  substances  also  produce  this  effect. 

If  from  experiments  we  pass  to  observations  on  the 
sick,  we  see  that  all  cerebral  affections  are  foreign  to  the 
organic  muscular  system.  Wounds  of  the  head  with  de- 
pression, fungi  of  the  brain,  effusions  of  blood,  pus  and 
serum,  apoplexy,  &c.  affect  exclusively  the  voluntary 
muscles,  the  action  of  which  they  increase,  weaken  or 
destroy.  In  the  midst  of  this  general  derangement  of  ani- 
mal life,  the  organic  remains  unaffected.  The  paroxysm 
of  mania  and  malignant  fever  likewise  proves  this  fact. 
Who  docs  not  know  that  in  this  last  the  pulse  is  often- 
times scarcely  altered,  that  sometimes  even  it  is  slo'Wer  ? 

Frequently  in  diseases  of  the  head,  there  are  spasmodic 
vomitings  ; the  action  of  the  heart  is  accelerated  in  cere- 
bral inflammations,  &c.  But  these  are  sympathetic  phe- 
nomena which  happen  in  the  organic  muscles,  as  they  do 
in  all  the  other  systems  ; they  may  not  appear  nor  be  de- 
veloped ; a thousand  irregularities  are  observed  in  their 
progress.  Whereas  the  contraction  of  the  muscles  of  ani- 
mal life  by  affections  of  the  brain  is  a constant,  invariable 
phenomenon,  which  nothing  disturbs,  and  the  develop- 
ment of  which  nothing  prevents,  because  the  means  of 
communication  are  always  the  same  between  the  affected 
organ  and  the  one  that  moves. 

If  in  the  examination  of  the  phenomena  relative  to  the 
cerebral  influence  upon  the  organic  muscles,  we  follow  an 
inverse  order,  that  is  to  say,  that  in  the  affections  of  these 
muscles  we  examine  the  state  of  the  brain,  we  observe 
the  same  independence  ; consider  most  vomitings,  the 


OF  ORGANIC  LIFE. 


19 


irregular  motions  of  the  intestines  which  take  place  in 
diarrhoeas,  those  especially  which  form  the  iliac  passion, 
&c.  ; observe  the  heart  in  the  agitations  of  fevers,  in  the 
irregular  palpitations  of  which  it  becomes  frequently  the 
seat,  &c. ; in  these  derangements  of  the  organic  muscles, 
you  will  very -seldom  find  signs  of  lesions  of  the  cerebral  or- 
gan ; it  is  calm,  while  every  thing  is  disordered  in  organic 
life.  Cullen  thought  that  in  syncope  the  action  of  the 
brain  ceased  first,  and  that  that  of  the  heart  was  afterwards 
consequently  suspended.  It  is  precisely  the  reverse  in 
the  greatest  number  of  cases.  The  heart,  at  first  affected, 
ceases  to  act ; now  its  action  being  essential  to  that  of 
the  brain,  whether  from  the  motion  it  communicates  to 
it,  or  from  the  red  blood  it  sends,  the  functions  of  this 
last  are  suddenly  suspended  and  the  whole  animal  life 
ceases.  This  is  remarkable  especially  in  the  syncopes 
that  arise  from  the  passions,  in  those  from  hemorrhages, 
polypi,  great  evacuations,  &c.  I refer  upon  this  subject 
to  my  Treatise  upon  Life  and  Death. 

If  from  the  influence  of  the  brain  we  pass  to  that  of 
the  nerves,  we  find  new  proofs  of  the  absence  of  animal 
contractility  in  the  organic  muscles.  The  most  of  these 
muscles  receive,  as  we  have  seen,  two  species  of  nerves, 
the  one  cerebral,  the  other  from  the  ganglions. 

The  heart,  the  stomach,  the  rectum  and  the  bladder  are 
evidently  entered  by  the  first  species  of  nerves ; now  by 
cutting,  or  irritating  in  any  way  the  cardiac  filaments  of 
the  par  vagum,  the  heart  experiences  no  alteration  from 
it ; its  motion  is  neither  retarded,  nor  accelerated.  The 
division  of  both  branches  of  the  par  vagum  is  fatal,  it  is 
true,  but  not  until  after  some  days  ; and  I doubt  whether 
it  is  by  tlie  heart  that  death  commences  in  this  case.  The 
principal  phenomena  consequent  upon  this  division  show 
a great  embatrassment  in  the  lungs,  a great  difficulty  of 
breathing ; the  circulation  appears  to  be  troubled  only  in 
consequence. 


20 


MUSCULAR  SYSTEM 


The  same  nerves  going  to  the  stomach,  the  same  ex- 
periment serves  to  prove  the  cerebral  influence  upon  this 
viscus.  Now  the  division  of  that  of  one  side  is  usually 
nothing  upon  it ; that  of  both  soon  produces  a remark- 
able derangement  in  it.  But  this  derangement  is  wholly 
difierent  from  that  wliich  follows  the  section  of  the  tierve 
of  a muscle  of  animal  life,  which  becomes  suddenly  im- 
moveable, whilst  that  on  the  contrary  the  stomach  not 
communicating  with  the  brain  except  by  the  par  vagum, 
seems  to  acquire  in  an.  instant  an  increase  of  power;  it 
contracts  and  hence  the  spasmodic  vomitings  that  are  al- 
most always  observed  during  the  two  or  three  days  that 
the  animal  survives  the  experiment,  vomitings  that  I 
have  constantly  noticed  in  dogs,  and  which  Haller  and 
Cruikshank  had  before  observed.  It  appears  then  from 
this,  that  though  the  brain  has  a real  influence  upon  the 
stomach,  this  influence  is  of  a nature  wholly  different 
from  that  which  it  exerts  upon  the  voluntary  muscles. 
I would  observe  however  that  the  irritation  of  one  branch 
of  the  par  vagum,  or  of  both,  makes  the  stomach  imme- 
diately contract,  as  happens  in  a voluntary  muscle  when 
we  Irritate  its  nerve.  It  is  necessary,  in  order  to  make 
this  experiment,  to  open  the  abdomen  of  a living  animal, 
and  afterwards  to  irritate  the  eighth  pair  in  the  region  of 
the  neck,  so  as  to  have  in  sight  the  organ  that  we  make 
contract. 

The  bladder  and  the  rectum  appear  to  approximate' the 
voluntary  muscles,  in  their  relation  with  the  brain,  more 
than  the  stomach  and  the  heart.  We  know  that  falls  on 
the  sacrum,  from  which  arises  a shock  of  the  inferior  part 
of  the  spinal  marrow,  produce  retention  of  urine ; that 
they  strike,  as  it  were,  this  organ  with  the  same  paralysis 
as  the  inferior  extremities,  which  then  also  cease  to  move. 
Yet  as  the  bladder  is  very  powerfully  assisted  in  its  func- 
tions by  the  abdominal  muscles,  by  the  levator  ani  and 
other  voluntary  muscles  which  surround  it,  the  immobility 


OF  ORGANIC  LIFE. 


21 


of  these  muscles  contributes  much  to  the  inability  to  evac- 
uate the  urine.  That  which  makes  me  think  so,  is  that, 
1st,  the  irritation  of  the  spinal  marrow  towards  its  infe- 
rior part  which  puts  in  motion  all  the  voluntary  muscles 
of  the  inferior  extremities  and  of  the  pelvis,  does  not  pro- 
duce any  effect  upon  this  part.  I have  convinced  myself 
of  this  fact  many  times  upon  dogs  and  guinea-pigs.  2d. 
By  irritating  the  nerves  coming  from  the  sacral  foramina 
and  going  to  the  bladder,  nerves  that  it  is  often  very  diffi- 
cult to  find,  on  account  of  the  blood  in  an  animal  recently 
killed,  I have  seen  this  muscle  remain  immoveable.  On 
the  contrary  all  these  nerves  having  been  cut,  the  injec- 
tion of  a fluid  slightly  stimulant  makes  it  contract  with 
force.  3d.  In  experiments  upon  living  animals,  as  in  surgi- 
cal operations,  the  violence  of  the  pain  which  sometimes 
produces  spasmodic  contractions  of  all  the  muscles  of  ani- 
mal life,  frequently  occasions  an  involuntary  discharge  of 
urine.  Now  in  these  cases  it  is  not  the  bladder  that  is 
convulsed  ; for  if  in  an  experiment  this  phenomenon  takes 
place,  open  the  abdominal  parietes,  in  an  instant  the  flow 
of  urine  ceases,  because  on  the  one  hand  the  muscles  of 
these  parietes  cannot  act  upon  the  intestines  and  press 
them  against  the  bladder,  and  because  on  the  other  the 
levator  ani  which  contacts  and  raises  this  organ,  has  no 
resisting  point  against  which  it  can  compress  it  above. 
Observe  in  fact  that  in  strong  jets  of  urine,  the  bladder  is 
placed  between  two  Opposite  efforts,  one  superior,  which 
is  the  gastric  viscera  pressed  by  the  diaphragm  and  the 
abdominal  muscles,  the  other  inferior,  which  is  especially 
the  levator  ani  which  acts  by  contracting  from  below 
above,  whilst  the  opposite  effort  acts  from  above  below  ; 
now  these  two  efforts  are  evidently  under  the  cerebral  in- 
fluence. I have  very  frequently  had  occasion  to  observe 
the  bladder  full  of  urine  in  a living  animal  whose  abdo- 
men was  opened ; I have  never  seen  it  contract  with  suf- 
ficient violence  to  expel  the  fluid. 


^2 


MUSCULAR  SYSTEM 


I do  not  deny  but  tliat  the  bladder,  by  the  nerves  it 
receives  from  the  sacral  plexuses,  is  to  a certain  extent  a 
voluntary  muscle ; but  I say  that  it  is  principally  by  forces 
accessory  to  its  own  and  necessary  to  its  functions,  that 
it  is  subjected  to  the  will ; that  the  animal  contractility  is 
much  greater  in  its  functions  than  the  sensible  organic 
contractility.  How  then  is  the  urine  retained  in  this  or- 
gan, or  expelled  from  its  cavity  at  will  ? In  this  way ; 
when  the  urine  falls  into  the  bladder,  and  is  there  on  the 
one  hand  but  a short  time,  and  on  the  other  only  in  small 
quantity,  it  is  not  then  an  irritant  sufficiently  powerful  to 
produce  the  exercise  of  the  sensible  organic  contractility. 
The  effort  which  the  bladder  makes  is  so  small,  that  it 
cannot  overcome  the  resistance  of  the  urethra,  which 
being  shut  by  the  contractility  of  texture,  must  be  dilated 
by  the  impulse  communicated  to  the  urine.  In  order' to 
void  this  fluid,  there  must  then  be  added  to  the  contrac- 
tion of  the  bladder  that  of  the  surrounding  voluntary 
muscles ; now  the  least  effort  of  these  muscles  is  suffi- 
cient to  overcome  the  resistance  of  the  urethra.  But  if 
the  urine  is  in  great  quantity  in  the  bladder,  and  it  has 
acquired  by  remaining  in  it  a long  time  that  deep  colour 
which  indicates  the  concentration  of  its  principles,  then 
the  irritation  that  it  produces  on  the  organ  brings  power- 
fully into  action  the  sensible  organic  contractility  ; the 
bladder  contracts,  and  in  spite  of  the  animal,  there  is  an 
evacuation  of  urine. 

In  the  rectum,  in  which  the  excrements  have  not  a 
long  canal,  but  only  a simple  opening  to  pass,  this  is  fur- 
nished with  a sphincter  which  is  wanting  in  the  urethra. 
This  sphincter  habitually  closed  must  be  dilated  by  the 
impulse  communicated  to  the  excrements.  When  they 
are  in  the  rectum  a short  time  and  in  small  quantity,  the 
sensible  organic  contractility  is  not  brought  into  action 
with  sufficient  power  to  expel  them;  it  requires  the 
action  of  the  neighbouring  voluntary  muscles.  If  this 


OF  ORGANIC  LIFE. 


25 


action  is  not  determined  by  the  influx  from  the  brain,  the 
excrements  remain  in  the  intestines ; hence  how,  for 
some  time,  we  retain  them  at  will.  But  as  they  increase 
in  quantity,  and  become  more  acrid  by  remaining  and 
consequently  more  irritating,  then  the  sensible  organic 
contractility  strongly  brought  into  action,  empties  the  in- 
testine involuntarily.  If  the  sphincter,  which  is  volun- 
tary, is  paralyzed,  there  will  be  incontinence,  because  no 
resistance  is  opposed  to  the  tendency  of  the  rectum  to 
contract,  a tendency  which  though  feeble  as  long  as  it  is 
but  partly  filled,  is  however  always  real. 

From  what  we  have  said,  it  appears  evidently  that  the 
bladder  and  rectum,  though  receiving  cerebral  nerves, 
are  yet  less  influenced  by  the  brain  than  it  at  first  view 
appears,  and  that  there  is  evidently  between  them  and 
the  voluntary  muscles  a very  great  difference.  They  are 
not  mixt,  as  it  is  called  ; they  approach  the  organic  muscles 
infinitely  nearer  than  the  others ; I doubt  even  whether 
if  no  accessory  power  acted  with  and  compressed  them, 
the  mind  could  by  the  nerves  which  come  from  the  sacral 
plexuses,  make  them  contract  at  will.  I have  never  seen 
an  animal  void  his  excrements  when  the  abdomen  was 
open. 

Let  us  conclude  from  all  that  has  been  thus  far  said, 
that  the  cerebral  nerves  which  go  to  the  organic  muscles 
have  upon  them  an  influence  which  by  no  means  resem- 
bles that  of  the  cerebral  nerves  going  to  the  muscles  of 
animal  life.  I am  ignorant  moreover  of  the  nature  of 
this  influence. 

All  the  organic  muscles  receive  nerves  from  the  gang- 
lions, both  the  preceding  ones  which  are  also  penetrated 
by  the  cerebral  nerves,  and  the  small  intestines,  and  tbje 
coecum,  colour,  &c.  which  are  exclusively  pervaded  by 
them.  Now  by  cutting,  tying  or  irritating  in  any  man- 
ner these  nerves,  by  stimulating  the  ganglions  from  which 
they  go,  by  destroying  or  burning  them  with  a concen- 


24 


MUSCULAR  SYSTEM. 


trated  acid  or  alkali,  the  muscle  remains  in  its  natural 
state  ; its  contractions  are  neither  accelerated  nor  retarded. 

I have  not  been  contented  with  ordinary  agents  in  con- 
vincing myself  of  the  deficiency  of  real  action  of  the 
nerves  upon  the  organic  muscles ; a fact,  which  all  good 
physiologists  have  always  admitted,  notwithstanding  the 
opinions  hazarded  by  some  physicians  who  apply  the 
vague  term  of  nervous  influence  to  organs  which  are  not 
susceptible  of  it. 

I have  then  employed  galvanism,  and  I am  convinced 
that  it  has  very  little,  almost  no  power,  in  putting  into 
action  muscular  contractions  in  organic  life,  whilst  it  is 
the  most  powerful  agent  in  animal  life.  I shall  not  here 
relate  my  experiments  upon  this  subject ; they  will  be 
read  in  my  Researches  upon  Death. 

We  can  conclude  from  all  that  precedes,  that  the  cere- 
bral and  nervous  influence  upon  the  organic  muscles  is 
not  known  to  us  ; that  it  does  not  act  as  upon  the  volun- 
tary muscles.  It  is  however  real  to  a certain  extent,  since 
it  is  necessary  that  the  nerves  which  enter  into  the  com- 
position of  these  muscles  should  be  of  some  use  ; but  we 
are  ignorant  of  this  use. 

Organic  Properties. 

The  organic  sensibility  is  strongly  characterized  in  the 
muscles  of  which  we  are  treating.  Before  the  sensible 
organic  contractility  is  developed  in  them,  it  is  necessary 
that  this  should  be  put  in  action.  But  as  these  two  pro- 
perties are  not  separated,  as  in  their  exercise  they  always 
succeed  each  other,  what  we  are  going  to  say  of  sensible 
organic  contractility  will  apply  also  to  the  sensibility  of 
the  same  nature. 

Insensible  organic  contractility  or  tone,  exists  in  the 
muscular  system,  to  a degree  necessary  for  its  nutrition  i 
but  it  does  not  exhibit  in  it  any  thing  peculiar. 


OF  ORGANIC  LIFE. 


25 


It  is  the  sensible  organic  contractility  that  is  the  pre- 
dominant property  in  this  system,  all  the  functions  of 
which  rest  almost  entirely  upon  this  contractility,  as  all 
the  functions  of  the  preceding  muscular  system  are  de- 
rived as  it  were  from  the  animal  contractility.  We  shall 
now  examine  more  in  detail  this  essential  property,  with 
regard  to  which  physiology  owes  so  much  to  the  illustri- 
ous Haller.  We  can  consider  it  in  three  relations;  1st,  in 
tlie  stimuli  ; 2d,  in  the  organs ; 3d,  in  the  action  of  the 
first  upon  the  second. 

Of  the  Sensible  Organic  Contractility  considered  in 
relation  to  Stimuli. 

Stimuli  are  natural  or  artificial.  The  action  of  the  first 
is  continual  during  life;  upon  them  turn  in  part  the  or- 
ganic phenomena ; they  place  in  action  the  muscles,  which 
without  them  would  be  immoveable ; they  are  as  it  were 
to  these  organs  what  pendulums  are  to  our  machines ; 
they  give  the  impulse.  The  second  can  hardly  have  effect 
until  after  death,  or  in  our  experiments. 

Natural  Stimuli. 

These  stimuli  are  blood  for  the  heart,  urine  for  the 
bladder,  aliments  and  excrements  for  the  gastric  organs. 
Every  organic  muscle  has  a body,  which,  habitually  in 
contact  with  it,  supports  its  motions,  as  every  animal  mus- 
cle habitually  in  relation  with  the  brain,  borrows  from  it 
its  powder  of  motion.  The  natural  stimuli  support  the 
organs  at  the  same  degree  of  mobility  while  they  remain 
the  same.  All  things  being  equal  on  the  part  of  the  or- 
gans, the  pulse  does  not  vary,  the  digestive  periods  con- 
tinue for  the  same  length  of  time,  the  intervals  between 
the  excretion  of  urine  are  equal,  whilst  the  blood,  the 
chyle  or  the  urine  exhibit  no  differences.  But  as  these 
4 


VOL.  III. 


26 


MUSCULAR  SYSTEM 


substances  experience  an  infinite  number  of  varieties,  the 
organs  preserving  the  same  degree  of  sensibility,  have 
yet  frequent  changes  in  their  motion. 

At  the  instant  chyle  enters  the  blood  during  digestion, 
the  pulse  changes,  because  the  heart  is  differently  irri- 
tated. We  observe  the  same  phenomenon  under  dif- 
ferent circumstances  ; 1st,  in  re-absorptions  in  which  pus 
goes  into  the  mass  of  blood  ; 2d,  in  the  injection  of  dif- 
ferent fluids  in  the  veins,  injections  that  were  so  fre- 
quently made  in  the  last  age,  at  the  period  of  experiments 
upon  transfusion,  and  which  I have  also  had  occasion  to 
make  with  other  views  which  I shall  mention  ; 3d,  in 
inflammatory  diseases  in  which  the  blood  takes  a peculiar 
character  that  is  yet  but  little  known,  and  which  occa- 
sions the  formation  of  the  pleuritic  buff ; 4th,  in  various 
other  affections,  in  which  the  nature  of  this  fluid  is  re- 
markably altered ; 5th,  in  the  passage  of  the  red  blood 
into  the  system  with  black  blood.  I have  observed  that 
in  putting  a curved  tube  into  tbe  carotid  of  one  side  and 
tbe  jugular  of  the  opposite  of  a large  dog,  so  that  one 
forces  blood  into  the  other,  the  passage  of  the  red  blood 
into  the  veins  is  not  fatal  like  that  of  the  black  blood  into 
the  arteries ; but  there  is  almost  always  at  first  an  accele- 
ration of  the  motions  of  the  heart. 

The  influence  of  the  degeneracy  of  the  fluids  in  dis- 
eases has  no  doubt  been  exaggerated  ; too  frequent  a 
source  of  morbid  derangements  has  been  placed  in  this 
portion  of  the  economy.  But  it  cannot  be  denied,  that 
according  to  the  different  alterations  that  the  fluids  ex- 
hibit, they  may  be  capable  of  exciting  differently  the  solids 
that  contain  them.  We  know  that  in  the  same  individual, 
and  with  the  same  mass  of  aliments,  digestion  varies  from 
one  day  to  another  in  the  duration  of  its  periods  ; that 
some  aliments  prolong  and  others  accelerate  it ; that  some 
remain  very  long  in  the  stomach,  as  it  is  said,  and  others 
as  it  were  only  pass  through  it.  Now  in  all  these  cases 


OF  ORGANIC  LIFE. 


27 


tlie  organ  remains  the  same,  the  fluid  only  varies.  Accord- 
ing as  the  kidney  secretes  urine  more  or  less  acrid  and 
consequently  more  or  less  irritating,  the  bladder  retains 
it  for  a longer  or ' shorter  time.  Such  is  oftentimes  its 
stimulating  qualities,  that  the  moment  it  comes  into  this 
organ  it  is  involuntarily  rejected.  Shall  I speak  of  emet- 
ics and  evacuants  by  the  intestinal  canal,  the  eflects  of 
which  are  so  variable  ? We  know  that  the  words  drastic, 
purgative,  laxative,  &c.  indicate  the  different  degrees  of 
the  stimulating  qualities  which  certain  substances  intro- 
duced into  the  alimentary  canal  exhibit,  degrees  which 
are  to  be  considered  abstractedly  from  those  of  the  sensi- 
bility of  the  organs  ; this  in  fact  can  be  such,  that  a laxa- 
tive may  produce  greater  effects  than  a drastic  purge. 

Not  only  the  quality,  but  also  the  quantity  of  the  fluids 
contained  in  the  organic  muscles,  has  an  influence  upon 
their  contractility.  1st.  The  word  plethora  is  certainly 
employed  too  loosely  in  medicine  ; but  we  cannot  doubt 
that  the  state  which  it  expresses  sometimes  exists  ; now 
the  more  blood  there  is  in  the  heart,  the  more  are  its 
contractions  accelerated.  2d.  I have  many  times  made 
transfusion  in  dogs,  whether  with  a view  to  that  alone, 
or  in  researches  relative  to  respiration  and  circulation. 
Now  I have  always  observed,  that  by  not  opening  a vein, 
to  empty  the  blood  as  fast  as  the  external  jugular  receives 
it  (for  I always  choose  this  vein  for  the  experiment)  by 
thus  producing  consequently  an  artificial  plethora,  I have, 
I say,  always  observed  that  the  motion  of  the  heart  was 
accelerated.  I have  even  seen  the  eye  of  a dog  become 
bright  and  as  it  were  inflamed  ; in  others  this  pheno- 
menon has  not  been  observed.  3d.  We  know  that  in 
running,  in  which  all  the  muscles  by  contracting  press 
out  from  all  sides  the  venous  blood  contained  in  their  tex- 
ture, this  which  enters  the  heart  in  abundance,  makes 
it  palpitate  powerfully.  4th.  There  is  not  doubt  but 
tliat  the  quantity  of  urine  and  excrements  as  much  and 


28 


MUSCULAR  SYSTEM 


more  than  their  quality,  is  for  the  bladder  and  the  rectum, 
a cause  of  involuntary  contraction.  5th.  We  know  the 
serious  consequences  that  arise  from  giving  emetics  and 
cathartics  in  too  large  doses.  6th.  A glass  of  tepid  water 
often  does  not  produce  vomiting  when  a pint  will  bring 
it  on  powerfully,  &c.  &c. 

Artificial  Stimuli. 

The  artificial  stimuli  are  in  general  all  the  bodies  in 
nature.  Such  is  in  fact  the  essence  of  organic  contrac- 
tility, that  a muscle  because  it  is  in  contact  with  a body 
to  which  it  is  not  accustomed,  instantly  contracts.  If  the 
muscles  are  not  irritated  by  the  organs  that  surround  them 
and  with  which  they  are  in  relation,  it  is  because  habit 
has  blunted  the  sensation  which  arises  from  this  relation. 
But  when  these  organs  change  their  modifications,  when 
extracted  from  the  body  of  the  animal,  they  become  cold, 
and  are  afterwards  applied  to  the  organic  muscles  laid 
bare,  they  will  make  them  contract. 

Caloric,  by  its  absence  which  constitutes  cold,  as  by  its 
presence  from  which  arises  heat,  can  equally  excite  the 
muscles  and  in  general  all  the  organs.  At  the  instant  we 
open  the  thorax  or  the  pericardium  of  a living  animal, 
the  heart  is  agitated  with  a suddenly  increased  force  ; it 
is  because  the  air  acts  upon  it,  and  it  passes  from  the 
temperature  of  the  body  to  another  which  is  different. 
All  the  aeriform  fluids,  light,  all  fluids,  &c.  are  stimuli  of 
the  muscles.  If  we  see  the  heart  emptied  of  blood,  the 
stomach  and  intestines  deprived  of  the  substances  that 
ordinarily  enter  them,  contract  with  more  or  less  force 
when  they  have  been  taken  out  of  the  body,  it  is  because 
the  surrounding  medium,  and  the  substances  with  which 
it  is  charged,  contribute  to  produce  this  efiTect;.  they  are 
then  the  stimuli  of  these  organs. 

In  general  the  artificial  stimuli  act  in  different  ways ; 
1st,  by  their  simple  contact ; 2d,  by  tearing  or  cutting 


OF  ORGANIC  LIFE, 


29 


mechanically  the  fibres;  3d,  by  tending  to  combine  with 
them;  4th,  there  are  some  of  whose  mode  of  action  we 
are  completely  ignorant;  such  for  example  is  electricity. 

When  the  stimuli  act  only  by  simple  contact,  the  fluids 
are,  all  things  being  equal,  more  efficacious  than  the 
solids,  because  they  stimulate  by  a greater  number  of 
points  ; as  they  irritate  not  only  the  surfaces  of  the  organ, 
but  penetrate  also  into  the  interstices  of  the  fibres.  The 
solids  produce  an  eSect  in  proportion  to  the  extent  of 
their  excitement,  to  the  greater  or  less  pressure  that  they 
exert,  to  their  density,  their  softness,  &c.  They  are 
almost  always  fluid  substances  that  nature  employs  for 
stimuli  in  the  ordinary  state. 

Tearing  is  a mode  of  excitement  more  active  than  con- 
tact. The  heart,  the  intestines  often  inert  when  they  are 
only  touched  by  the  scalpel,  contract  powerfully  when 
the  point  of  it  excites  them.  Cutting  produces  a less 
sensible  effect  than  tearing.  Cut  transversely,  the  fibres 
oscillate  and  are  agitated  only  by  the  sensible  organic 
contractility,  whilst  by  the  contractility  of  texture  they 
experience  an  evident  retraction. 

Chemical  excitement  is,  in  the  greatest  number  of  cases, 
the  most  advantageous ; but  it  is  necessary  here  to  distin- 
guish that  which  belongs  to  the  horny  hardening,  from 
that  which  is  the  effect  of  irritability  brought  into  action. 
1st.  Plunge  a frog  without  skin  and  alive  into  a concen- 
trated acid  ; instantly  every  thing  is  disorganized  ; the 
reagent  acts  so  strongly,  that  we  can  distinguish  neither 
horny  hardening  nor  contractility.  2d.  Weaken  the  acid 
a little  and  plunge  into  it,  the  inferior  extremities  only 
of  a frog  ; in  an  instant  they  stiffen  by  the  contraction  of 
the  extensors,  which  overcome  the  flexors  ; for  in  this 
experiment,  this  is  almost  a constant  phenomenon ; with- 
draw the  animal  ; its  thighs  remain  immoveable,  life  has 
been  extinguished  in  them  ; the  contraction  that  has  come 
on  is  a horny  hardening,  and  not  a vital  phenomenon.  A 


30 


MUSCULAR  SYSTEM 


dead  frog  plunged  into  the  same  liquor  experiences  the 
same  phenomenon.  3d.  Weaken  the  acid  still  more ; the 
instant  the  animal  is  plunged  into  it  its  limbs  contract ; 
but  relaxation  succeeds  the  contractions ; these  are  alter- 
nate motions  ; it  is  the  irritability  that  begins  to  be  put 
into  action.  Yet  if  the  acid  is  not  very  weak,  some 
marks  of  the  horny  hardening  still  remain,  and  the  ani- 
mal  has  a stiffness  in  the  motions  of  the  inferior  extremi- 
ties, the  evident  result  of  the  first  degree  of  this  horny 
hardening.  4tli.  Finally,  if  the  acid  is  very  weak,  it  be- 
comes a simple  irritant  which  puts  in  action  the  sensible 
organic  contractility,  without  altering  the  texture  of  the 
fibres ; the  animal  after  coming  out  of  the  fluid  preserves 
the  same  power  of  motion. 

These  experiments  which  it  would  be  easy  to  multiply 
upon  animals  witli  warm  blood,  but  which  I have  never 
attempted  upon  them,  evidently  show  what  belongs  to 
the  horny  hardening,  and  what  is  the  effect  of  vital  con- 
traction. Yet  there  is  not  an  exact  limit  between  them, 
and  there  is  one  degree  of  weakness  of  the  acid  in  which 
these  two  causes  of  motions  are  confounded. 

There  is  a mode  of  excitement  to  which  authors  have 
not  paid  attention  ; it  may  be  called  negative ; it  is  that 
of  which  I spoke  just  now  on  the  subject  of  caloric,  the 
privation  of  which  is  oftentimes  a very  active  stimulant. 
In  tlie  different  experiments  that  I have  had  occasion  to 
make,  this  has  frequently  struck  me.  Apply  a stimulant 
to  a muscle,  it  contracts ; but  at  the  end  of  some  time 
the  motion  ceases,  though  the  contact  continues  ; remove 
the  stimulant,  the  motion  frequently  returns  in  an  instant. 
In  general,  nothing  is  more  common  in  the  heart,  the  in- 
testines, &c.  than  their  contractions  ceasing  under  the  con- 
tinued action  of  a stimulant,  and  returning  instantly  upon 
its  absence.  I confess  that  this  phenomenon  is  not  as  in- 
variable and  constant  as  that  of  the  contraction  produced 
b}"  the  application  of  tlie  stimulus  which  succeeds  a state 


OF  ORGANIC  LIFE. 


31 


of  non-excitement;  but  this  happens  very  often.  We 
might  say  that  the  organic  sensibility  is  in  this  case  like 
the  animal , that  every  new  state  affects  it,  whether  it  be 
positive  or  negative.  The  passage  from  non-excitement 
to  excitement  is  more  lively ; but  the  opposite  passage  is 
not  less  when  it  is  sudden.  Moreover  this  manner  of 
describing  the  sensible  organic  contractility  in  exercise, 
deserves  some  further  experiments. 

Of  the.  Sensible  Organic  Contractility  considered  in 
relation  to  the  Organs. 

The  sensible  organic  contractility,  considered  in  the 
organ  in  which  it  has  its  seat,  exhibits  numerous  varieties 
which  are  relative  ; 1st,  to  the  diversity  of  texture ; 2d, 
to  age;  3d,  to  sex;  4th,  to  temperament,  &c. 

First  Variety.  Diversity  of  the  Muscular  Texture. 

The  animal  contractility  is  everywhere  the  same  in  the 
voluntary  muscles,  because  their  organization  is  uniform. 
All  things  being  equal  as  to  the  number  and  length  of 
the  fibres,  the  phenomena  of  contraction  are  exactly  the 
same  everywhere ; here,  on  the  contrary,  the  varieties  of 
texture  inevitably  produce  varieties  in  the  vital  properties. 

Each  involuntary  muscle  is  at  first  especially  in  rela- 
tion with  the  fluid  which  ordinarily  acts  as  its  stimulus. 
The  blood  alone  can  regularly  support  the  motions  of  the 
heart.  Let  this  fluid  be  altered  in  any  manner,  the  con- 
tractions become  irregular.  All  foreign  substances  forced 
into  the  veins  produce  this  phenomenon.  The  urine, 
which  supports  with  harmony  the  motions  of  the  bladder, 
would  disturb  those  of  the  heart,  if  it  circulated  in  its 
cavities.  The  blood,  more  soft  in  appearance  than  the 
urine,  can  agitate  convulsively  the  bladder,  if  it  happens 
to  be  in  it.  I took  care  with  Desault  of  a patient  afiected 
for  a long  time  with  retention  of  urine,  and  whom  he  had 
cut  for  a very  large  stone.  After  the  operation,  the  urine 


32 


MUSCULAR  SYSTEM 


remained  stagnant  in  the  bladder  as  long  as  it  was  alone, 
but  when  a little  blood  entered  this  organ,  it  co^ntracted 
involuntarily  and  the  bloody  urine  was  evacuated.  The 
excrements,  which  could  continue  for  a long  time  in  the 
rectum  without  making  it  contract,  would  make  the 
stomach  heave  in  an  instant,  &c.  All  these  phenomena 
are  to  be  referred  to  varieties  of  sensibility  of  the  iriucous 
membranes,  varieties  which  we  shall  notice  again.  They 
prove  evidently  that  each  muscle  has  a degree  of  organic 
contractility  which  is  peculiar  to  it,  and  that  this  or  that 
fluid  of  the  economy  can  exclusively,  in  a natural  state, 
put  it  in  exercise  in  a regular  manner. 

Foreign  fluids  exhibit  the  same  result ; the  emetic 
which  makes  the  stomach  contract,  is  injected  with  im- 
punity into  the  bladder ; purgatives  do  not  produce  vom- 
iting, &c.  This  relation  of  foreign  fluids  with  the  sensi- 
ble organic  contractility  takes  place,  whether,  as  in  the 
preceding  case,  these  fluids  are  applied  to  the  mucous 
surfaces  corresponding  to  the  muscles,  or  whether  they 
come  to  the  muscles  by  the  circulation,  as  the  experi- 
ments have  proved  which  were  made  in  the  last  age  upon 
the  introduction  of  medicinal  substances  into  the  veins ; 
experiments  of  which  Haller  has  collected  a great  num- 
ber of  results.  We  have  seen  in  these  experiments,  the 
circulation  present  to  all  the  organs  sometimes  an  emetic, 
and  the  stomach  alone  contracts ; sometimes  a purgative, 
and  the  intestines  only  enter  into  action,  &c.  Taken  in 
by  cutaneous  absorption,  medicinal  substances  occasion 
the  same  phenomenon.  Applied  by  friction,  purgatives, 
emetics,  &c.  do  not  make  all  the  organic  muscles  contract, 
though  the  circulation  presents  them  to  all,  but  only  those 
with  which  their  sensibility  is  in  relation. 

In  the  various  affections  of  which  they  are  the  seat,  we 
see  the  organic  muscles  having  each  a peculiar  mode  of 
irritation  answer  to  each  stimulus,  and  remaining  deaf,  if 
we  may  so  say,  to  the  voice  of  the  others. 


OF  ORGANIC  LIFE'. 


S3 


Second  Variety,  •^ge. 

Age  modifies  wonderfully  the  sensible  organic  con- 
tractility. In  infancy  it  is  very  evident ; the  muscles 
answer  with  extreme  ' ease  to  the  stimuli ; the  bladder 
retains  the  urine  with  difficulty ; children  void  it  in  sleep 
involuntarily ; the  heart  contracts  with  a rapidity  of  which 
the  pulse  is  the  measure ; all  the  digestive  phenomena 
are  more  prompt ; hence  there  is  less  interval  between 
the  returns  of  hunger.  It  is  a phenomenon  analogous  to 
that  of  the  voluntary  muscles,  in  which  the  rapidity  of 
the  motions  is  found,  in  the  first  age,  connected  with  their 
small  degree  of  force. 

After  infancy,  the  susceptibility  of  the  muscles  to 
answer  to  their  stimuli,  is  constantly  diminishing;  thus 
all  the  great  phenomena  of  organic  life  are  continually  be- 
coming slower.  The  number  of  pulsations,  the  duration 
of  digestion,  the  longer  continuance  of  the  urine,  &c.  are 
the  thermometer  of  this  slowness. 

In  old  age  the  whole  is  weakened  ; the  action  of  th^ 
organic  muscles  gradually  diminishes.  Those  of  the  blad- 
der and  rectum  are  the  most  exposed  to  lose  their  con- 
tractile faculty  ; hence  the  retention  of  urine,  which  is  a 
frequent  companion  of  old  age  ; hence  also  the  accumula- 
tion of  fecal  matters  above  the  anus,  a disease  almost  as 
common  as  the  first  at  this  age  of  life,  though  it  has 
received  less  attention  from  practitioners.  Rich  people 
and  those  accustomed  to  the  luxury  of  the  table  are 
especially  subject  to  it.  I have  seen  much  of  it,  as  much 
even  as  of  retention  of  urine,  in  the  last  year  of  the 
practice  of  Desault.  The  intestines  and  the  stomach  lan- 
guish more  slowly  in  their  functions.  It  is  the  heart 
which  resists  the  most ; it  is  the  ultimum  moriens,  as  it 
has  been  the  first  in  exercise  ; the  duration  of  its  pulsa- 
tions measures  exactly  the  duration  of  organic  life. 

VOL.  III.  5 


34 


MUSCULAR  SYSTEM 


Third  Variety.  Temperament. 

Temperament  modifies  in  a remarkable  manner  organic 
contractility.  We  know  that  in  some  the  pulsations  are 
more  frequent,  the  digestive  and  urinary  phenomena  more 
rapid  ; that  in  others,  every  thing  is  marked  hy  more 
slowness  in  organic  life  ; now  these  varieties  have  evi- 
dently their  primitive  source  in  the  varieties  of  the  con- 
tractility of  the  heart,  the  stomach,  the  intestines,  &c- 
which  have  under  this  relation  a great  influence  in  the 
difference  of  the  temperaments.  With  respect  to  this 
there  are  two  essential  observations  to  be  made;  1st. 
The  varieties  of  force  of  the  organic  muscles  do  not 
always  coincide  with  those  of  the  muscles  of  animal  life. 
Thus  we  see  an  individual  with  feehly  developed  exterior 
forms,  with  an  evident  weakness  of  the  muscles  of  the 
extremities,  whilst  the  activity  of  digestion,  of  the  urin-' 
ary  evacuations,  &c.  announces  the  greatest  energy  in  the 
sensible  organic  contractility.  I would  remark  with 
regard  to  this,  that  the  heart  is  more  frequently  in  rela- 
tion of  force  witli  the  external  muscles  than  the  stomach, 
the  intestines  and  the  bladder.  A full  pulse,  well  de- 
veloped, is  usually  found  with  an  athletic  constitution  ; 
whilst  often  this  constitution  is  united  in  the  same  subject 
to  a feeble  gastric  system,  and  especially  the  force  of  this 
gastric  system  is  frequently  connected  with  external 
weakness.  This  fact,  which  the  different  temperaments 
demonstrate  to  us  in  man,  is  evident  in  the  series  of  ani- 
mals. Those  who,  like  the  carnivoi-ous  ones,  have  a very 
powerful  animal  muscular  system,  have  the  parietes  of 
the  gastric  cavities  like  membranes.  These  parietes  are 
strong  in  the  herbivorous  classes ; they  become  very  con- 
spicuous in  the  gallinaceous.  In  general,  mastication  over 
which  the  animal  contractility  always  presides,  is  in  ani- 
mals in  an  inverse  ratio  of  the  force  of  trituration  of  the 
stomach,  over  which  the  sensible  organic  contractility 
presides. 


OF  ORGANIC  LIFE. 


35 


2d.  The  varieties  of  this  propert)’-,  relative  to  tempera- 
ments^exhibit  another  phenomenon  almost  always  foreign 
to  the  animal  muscular  system.  In  fact  in  this  the  varie- 
ties are  always  general ; we  are  able  by  exercise  to 
^strengthen  this  or  that  muscular  region ; but  the  differ- 
ences of  forces  which  are  natural,  always  influence  the 
whole  system.  The  arms  and  the  legs,  the  thorax  and 
the  abdomen  are  uniformly  contractile  in  the  different 
divisions  of  the  muscles  that  belong  to  them.  On  the 
contrary,  it  is  rare  to  see  this  uniformity  in  the  involun- 
tary muscles.  One  almost  always  predominates  over  tl^e 
others  ; sometimes  it  is  the  heart,  sometimes  the  stomach 
and  sometimes  the  bladder.  The  gastric  viscera  even  are 
frequently  not  all  at  the  same  level  as  to  force.  The 
stomach  is  feeble  when  the  intestines  preserve  their  ordi- 
nary action  ; and  reciprocally  the  intestines  too  contrac- 
tile expel  immediately  fecal  matters  and  thus  produce  a 
diarrhoea,  though  the  stomach  may  perform  its  functions 
well.  This  essential  difference  in  the  two  muscular  sys- 
tems arises  from  the  circumstance  that  the  contractility  of 
one  depends  upon  a common  centre,  the  brain ; whilst 
that  of  the  other  on  the  contrary  has  its  principle  insulated 
in  each  organ  in  which  it  exists. 

Fourth  Variety.  Sex. 

Women  in  general  resemble  children  in  the  phenomena 
of  sensible  organic  contractility.  The  weakness  of  the 
motions  coincides  with  their  greater  rapidity  in  this  sex, 
all  whose  internal  muscles,  like  the  external,  are  more 
delicate  and  less  strongly  developed  than  in  man.  It 
might  be  said  that  the  contractile  power  of  the  womb  has 
been  formed  at  the  expense  of  the  forces  of  all  the  other 
organs.  In  experiments,  females  give  results  much  less 
decided  and  always  less  durable  than  males.  The  motions 
of  the  heart,  the  stomach,  the  intestipes,  &c.  cease  sooner ; 


36 


MUSCULAR  SYSTEM 


these  motions  are  less ; it  requires  stronger  stimuli  to 
produce  them,  &c. 

Fifth  Variety.  Season  and  Climate. 

Jn  winter  and  in  cold  climates,  in  which  the  cutaneous 
organ  contracted,  and  having  as  it  were  the  horny  hardness 
from  the  impression  of  the  surrounding  air,  has  but  a 
feeble  action,  all  the  internal  functions  more  active,  re- 
quire more  energy  in  the  forces  that  preside  over  them  ; 
all  the  digestive,  urinary  and  circulatory  phenomena  are 
more  evident.  I do  not  know  that  there  has  yet  been 
made  any  comparative  experiments  upon  irritability  in 
the  different  seasons  ; but  I am  persuaded  that  they  would 
give  different  results. 

Sensible  Organic  Contractility  considered  in  relation 
to  the  diction  of  Stimuli  upon  the  Organs. 

We  have  just  described  separately  the  stimulant  and 
the  organ  stimulated  ; each  being  separate  there  is  no 
effect  upon  the  sensible  organic  contractility  ; from  their 
union  alone  results  the  exercise  of  this  property.  What 
happens  in  this  union  ? We  know  not.  To  wish  to  know 
it,  would  be  to  wish  to  know  how  one  body  attracts 
another,  how  an  acid  combines  with  an  alkali,  &c.  In 
attraction,  affinity  and  irritability,  we  can  only  trace  the 
phenomena  to  the  action  of  bodies  upon  each  other.  This 
action  is  the  utmost  limit  of  our  researches. 

But  that  which  ought  not  to  escape  us  here  is,  that  in 
this  last  property,  the  action  is  never  immediate.  There 
is  always  between  the  stimulus  and  the  organ  something 
intermediate  which  receives  the  irritation ; this  inter- 
mediate organ  is  a delicate  membrane  and  continuous  with 
that  of  the  arteries  for  the  heart ; it  is  a mucous  surface 
for  the  gastric  viscera  and  the  bladder.  This  intermediate 
organ  is  more  susceptible  of  receiving  excitement  than 
the  muscle  itself.  I have  uniformly  observed  that  by 


OF  ORGANIC  LIFE. 


37 


irritating  the  internal  surface  of  the  heart,  its  contractions 
are  greater,  than  by  laying  its  texture  bare  externally  by 
removing  its  serous  covering  and  afterwards  stimulating 
it.  The  same  is  true  with  regard  to  the  organic  muscles 
of  the  abdomen. 

Is  there  between  the  intermediate  organ  excited  and 
the  organ  which  contracts,  any  nervous  communications 
that  transmit  the  impression  ? I think  not,  the  cellular 
texture  is  sufficient.  In  fact  the  serous  surfaces  and  the 
organic  muscles  have  only  this  texture  as  a means  of 
union.  The  life  of  tlie  first  is  in  no  way  connected  with 
that  of  the  others,  since  they  often  leave  them  as  we  shall 
see,  and  yet  they  can  transmit  excitement  to  them.  The 
pericardium  and  the  peritoneum,  irritated  in  their  portion 
corresponding  with  the  organ  that  we  wish  to  move,  pro- 
duce a contraction  in  it.  This  fact  is  known  to  all  those 
who  have  made  the  least  experiment ; it  is  almost  always 
in  this  way  that  we  stimulate  the  heart,  the  stomach,  the 
intestines,  the  bladder,  &c.  By  carrying  the  stimulus 
over  the  serous  surface  but  very  lightly,  and  so  as  not  to 
communicate  the  motion  to  the  fleshy  fibres,  we  obtain  a 
result.  Yet  simple  contact  is  not  sufficient  to  transmit 
tbe  irritation ; for  example,  by  leaving  the  external  layer 
of  the  pericardium  applied  to  the  heart  and  afterwards 
irritating  it,  the  organ  remains  immoveable.  If  we  sepa- 
I'ate  the  peritoneum  from  above  the  bladder,  so  as  to 
break  all  the  cellular  adhesions,  and  afterwards  reapply 
and  stimulate  it,  the  same  immobility  is  observed. 

When  the  intermediate  organ  that  receives  the  excite- 
ment is  diseased,  the  contractility  is  uniformly  altered. 
The  same  stimulus  produces  slow  or  rapid  contractions, 
according  as  the  affection  raises  or  diminishes  the  sensi- 
bility of  this  intermediate  organ.  A slight  inflammation 
of  the  exterior  of  the  bladder  produces  a kind  of  incon- 
tinence of  urine;  that  of  the  intestines  occasions  diar- 
rhoea, &c.  &c.  On  the  contrary,  old  catarrhs  of  the  blad- 


38 


MUSCULAR  SYSTEM 


der,  the  affections  in  which  weakness  of  the  mucous  sur- 
face of  this  organ  predominates,  are  the  frequent  causes 
of  retention. 

I would  observe  that  the  existence  of  this  intermediate 
organ  is  a I’emarkable  difference  between  the  sensible 
organic  contractility  and  the  insensible,  for  this  organ 
does  not  exist  in  this  last,  in  which  the  same  system  re- 
ceives the  impression  and  reacts  upon  the  body  that  has 
produced  it ; for  example,  in  the  glandular,  serous,  cuta- 
neous systems,  &c.  the  fluid  which  enters  them  for  secre- 
tion or  exhalation  produces  in  them  the  sensation,  which 
is  instantly  followed  by  the  reaction.  In  the  sensible 
contractility  on  the  contrary,  one  system  feels  and  an- 
other is  moved.  This  kind  of  mobility  is  less  removed 
from  that  of  animal  life,  in  which  the  organs  of  the  senses 
and  those  of  the  motion  being  wholly  different,  are  very 
distant  from  each  other. 

Sensible  Organie  Contraelility  considered  in  relation 
to  its  duration  after  Death. 

This  duration  is  longer  than  that  of  the  animal  con- 
tractility. When  the  spinal  marrow  is  irritated,  the  ex- 
ternal muscles  remain  immoveable,  whilst  the  internal 
ones  are  still  in  activity.  There  have  been  so  many  ex- 
amples related  of  this  duration,  Haller  has  multiplied  ex- 
periments so  much  upon  this  point,  that  there  is  no  occa- 
sion for  me  to  give  proofs  here  of  a fact  of  which  no  one 
can  any  longer  doubt.  To  this  duration  are  owing  the 
evacuations  of  fecal  matter  and  urine  which  often  take' 
place  an  instant  after  death  ; the  vomitings  that  are  ob- 
served in  some  subjects,  if  not  in  as  evident  a manner 
as  during  life,  at  least  sufficient  to  raise  the  aliments  into 
the  mouth  of  the  dead  body,  which  is  often  completely 
filled  with  them,  as  I have  frequently  seen. 

It  is  necessary,  in  relation  to  this  duration,  as  in  rela- 
tion to  that  of  the  animal  contractility,  to  distinguish  two 


OF  ORGANIC  LIFE. 


39 


species  of  death;  1st,  those  that  take  place  suddenly; 
2d,  those  which  are  the  consequence  of  long  disease. 

In  every  sudden  death,  produced  either  by  a violent 
lesion  of  the  brain,  as  in  apoplexy,  concussion,  compres- 
sion, effusion,  &c.  or  by  an  affection  of  the  heart,  as  in 
syncope,  a wound,  or  a ruptured  aneurism  ; or  by  a cessa- 
tion of  the  action  of  the  lungs,  as  in  asphyxia  from  dele- 
terious gases,  a vacuum,  submersion,  &c.  the  duration  of 
contractility  is  very  evident ; general  death  comes  on 
first,  then  the  organs  die  partially ; each  vital  force  is 
afterwards  successively  extinguished. 

In  every  kind  of  death  slowly  produced,  in  all  those 
especially  which  are  preceded  by  a disease  of  weakness, 
it  is  the  partial  death  of  each  organ  that  first  takes  place ; 
each  vital  force  is  weakened  and  extinguished,  gradually, 
before  the  cessation  of  them  as  a whole,  which  constitutes 
general  death,  comes  on ; when  this  death  takes  place, 
none  of  the  lives  peculiar  to  each  organ  remains,  whilst 
most  of  these  lives  continue  for  a Iqnger  or  shorter  time 
after  sudden  death. 

We  cannot  make  these  experiments  upon  dead  bodies 
which  we  rarely  have  in  the  hospitals  till  fifteen  hours  or 
more  after  death  ; but  by  killing  dogs  by  hunger,  which, 
when  long  continued,  becomes  a real  disease  that  lasts  in 
these  animals  eight,  ten  and  even  twelve  days,  I have  seen 
the  contractility  entirely  extinguished  at  the  moment  of 
death.  Dogs  have  been  often  brought  to  me  affected  with 
different  diseases,  especially  three  years  since  when  there 
was  a kind  of  epidemic  among  these  animals  ; now  by 
opening  them  at  the  instant  of  death,  by  killing  them 
even  some  time  before  and  thus  producing  a sudden  death 
wholly  different  from  that  which  happens  in  the  sound 
state  in  which  all  the  parts  are  uninjured  in  their  func- 
tions and  consequently  in  their  vital  forces,  I have  always 
seen  a constant  absence  of  contractility,  or  at  least  so 
greatly  weakened  that  it  appeared  to  be  nothing. 


40 


Muscular  system 


Many  physiologists  have  spoken  of  a general  convul- 
sion which  comes  on  in  the  organic  muscles  at  the  instant 
of  death,  of  a rising  of  the  heart,  the  stomach,  the  intes- 
tines, &c.  This  excess  of  action  is  sometimes  real  in 
sudden  deaths,  in  those  especially  that  we  produce  for 
our  experiments  ; it  is  very  rare  in  deaths  preceded  by  a 
long  disease  in  which  the  patient  is  extinguished,  as  it 
were,  insensibly,  and  passes  gradually  from  life  to  death. 
It  is  a fault  common  to  almost  all  authors,  to  generalize 
too  much  the  facts  observed  under  certain  circumstances. 
Many  false  consequences  are  the  results  of  it. 

Sympathies. 

No  organ  receives  more  easily  the  influence  of  others, 
than  the  organic  muscles ; all  however  are  not  equally 
susceptible  of  it.  The  heart  occupies  the  first  rank  in 
tliis  respect ; then  comes  the  stomach,  then  the  intestines, 
and  finally  the  bladder.  It  is  in  this  order  that  we  shall 
now  examine  this  influence. 

It  is  a remarkable  phenomenon,  that  every  kind  of 
affection  in  any  degree  strong,  arising  in  the  economy, 
alters  immediately  the  motions  of  the  heart.  The  least 
wound,  oftentimes  the  slightest  pain  are  sufficient  to  pro- 
duce derangements  in  it ; now  these  derangements  are  of 
two  kinds  ; sometimes  its  action  is  arrested  for  a moment ; 
hence  syncopes,  a mode  of  derangement  which  happens 
especially  in  violent  and  sudden  pains.  The  vulgar  ex- 
pression which  is  employed  in  these  cases,  viz.  “ my  heart 
is  failing,”  is  perfectly  true.  Sometimes,  and  this  is  the 
most  common  case,  this  action  is  accelerated  ; hence  the 
febrile  motions  so  frequent  in  all  the  local  affections,  mo- 
tions purely  sympathetic  and  which  cease  when  the  affec- 
tion disappears.  In  many  local  inflammations,  the  evil  is 
loo  circumscribed  to  admit  an  obstacle  to  the  course  of  the 
blood,  an  obstacle,  which  according  to  Boerhaave,  forces 
the  heart  to  redouble  its  action  to  surmount  it;  besides 


OF  ORGANIC  LIFE. 


41 


when  there  is  no  swelling,  but  only  pain  in  the  part,  and 
the  febrile  motion  comes  on,  it  is  there  clearly  a sympa- 
thetic phenomenon.  The  increase  of  the  action  of  the 
heart  may  depend  no  doubt  upon  a foreign  substance, 
which,  mixed  with  the  blood,  alters  and  renders  it  more 
irritating  5 it  may  be  owing  to  an  affection  of  the  substance 
of  the  organ  which  disposes  it  to  be  more  irritable ; but 
it  is  certainly  very  often  sympathetic,  and  depends  upon 
that  unknown  relation  which  connects  all  our  organs, 
upon  that  consensus  which  links  together  all  their  actions, 
and  places  them  in  reciprocal  dependance. 

I shall  say  as  much  of  the  stomach  ; though  its  sympa- 
thetic reaction  may  not  be  altogether  as  frequent  as  that 
of  the  heart,  yet  it  becomes  very  evident  under  many 
circumstances.  Most  local  affections,  especially  inflam- 
mations are  accompanied  with  sympathetic  vomitings. 
Various  fevers  have  in  their  commencement  similar 
vomitings.  It  is  in  the  hospitals  especially  that  we  fre- 
quently observe  these  phenomena.  Many  physicians 
have  not  considered  these  vomitings  as  merely  sympa- 
thetic, but  as  the  index  of  a bilious  aflfection,  founded  on 
this,  that  bile  is  then  almost  always  thrown  up.  But  in 
all  the  .animals  that  I have  opened,  I have  almost  always 
seen  the  stomach  when  empty  containing  a certain  quan- 
tity of  this  fluid  which  had  flowed  back  from  the  duo- 
denum ; other  authors  have  also  made  similar  observa- 
tions ; so  that  it  appears  that  in  the  state  of  vacuity,  the 
existence  of'  bile  in  the  stomach  is  a natural  phenomenon. 
Hence  it  is  not  astonishing,  that  in  the  commencement  of 
diseases,  and  even  in  their  course,  the  stomach  being 
sympathetically  excited  and  thus  becoming  the  seat  of 
vomiting,  more  or  less  of  this  fluid  should  be  thrown  up. 
It  would  be  brought  up  even  in  health  if  vomiting  is  then 
excited  by  an  emetic  ; this  is  what  sometimes  happens  in 
the  morning  when  the  stomach  is  empty,  if  any  cause 
foreign  to  an  affection  of  the  liver,  as  the  sight  of  a dis- 

VOL.  III.  6 


42 


MUSCULAR  SYSTEM 


gusting  object,  produces  vomiting  ; the  bile  then  comes 
out  like  every  thing  else  that  is  contained  in  the  stomach. 
1 do  not  say  that  oftentimes  the  liver  being  sympatheti- 
cally excited  in  the  commencement  of  diseases,  does  not 
furnish  more  bile,  that  this  superabundant  bile  flowing 
into  the  stomach,  does  not  make  this  viscus  contract ; hut 
certainly  this  is  not  most  commonly  the  case ; we  vomit 
bile  as  we  discharge  it  by  the  anus,  because  it  is  found  in 
the  stomach  and  intestines,  and  not  because  it  is  supera- 
bundant. If  vomiting  Avas  a natural  function,  the  bilious 
evacuations  in  this  way  would  he  as  natural  as  the  grey- 
ish tinge  of  the  excrements,  which  is  always  found  in  a 
state  of  health.  We  see  then,  from  this,  that  the  bilious 
vomitings  are,  in  many  cases,  purely  accessory,  and  that 
the  essential  phenomenon  is  the  sympathetic  contraction 
of  the  stomach. 

In  the  case  of  which  I have  just  spoken  there  is  no  gas- 
tric difficulty ; the  sympathetic  alteration  of  the  stomach 
only  extends  to  the  fleshy  fibres.  But  most  frequently 
this  gastric  difficulty  appears  at  the  beginning  of  diseases 
in  which  there  is  local  affection  ; sand-like  substances  are 
vomited  up  ; it  is  because  then  the  organ  essentially  affect- 
ed, the  lungs  for  example,  if  it  is  in  a peripneUmony,  has 
acted  sympathetically  not  only  on  the  fleshy  fibres,  but 
also  upon  the  mucous  membrane.  This  excited  increases 
its  secretion  ; hence  these  sand-like  substances,  which  are 
nothing  hut  the  mucous  juices  mixed  with  the  gastric 
fluid  and  witli  the  bile ; now  the  presence  of  these  sub- 
stances is  often  sufficient  to  make  the  stomach  contract, 
and  produce  vomiting  which  expels  them. 

From  this  it  is  evident  that  there  can  be  sympathetic 
Ammitings  without  gastric  difficulty,  and  sympathetic  gas- 
tric difficulty  with  a vomiting  immediately  produced.  In 
the  first  case  the  fleshy  fibres  feel  the  sympathetic  influ- 
ence of  the  affected  organ  ; in  the  second  it  is  the  mucous 
membrane.  But  how,  when  the  lungs,  the  pleura,  the 


OF  ORGANIC  LIFE. 


43 


skin,  &c.  being  affected,  does  the  stomach  come  into 
action  ? I have  said  that  the  word  sympathy  was  only  a 
veil  for  our  ignorance  in  respect  to  the  relations  of  the 
organs  to  each  other.  Vomitings  produced  by  erysipelas, 
phlegmon,  pleurisy,  peripneumony,  &c.  are  then  most 
often  an  effect  exactly  analogous  to  the  increase  of  the 
action  of  the  heart,  which  pi’oduces  fever.  They  resem- 
ble the  cerebral  derangement  from  which  arises  delirium, 
a derangement  which  is  much  more  rare,  &c.  All  these 
phenomena  indicate  that  the  other  organs  feel  by  reaction 
the  state  of  that  which  is  affected,  &c.  Physicians  who 
have  not  viewed  all  these  phenomena  in  a great  and  gen- 
eral manner,  have  confined  their  treatment  to  too  narrow 
bounds.  Much  attention  was  formerly  paid  to  the  sym- 
pathetic derangement  of  the  heart,  and  bleeding  was  much 
practised  in  the  beginning  of  diseases  ; for  some  years 
past  much  regard  has  been  had  to  the  sympathetic  de- 
rangement of  the  stomach,  and  emetics  are  frequently 
given ; perhaps  before  long,  more  attention  will  be  given 
to  the  weights  of  the  head,  pains  in  that  part,  watchful- 
ness, drowsiness,  &c.  which  are  very  common  sympa- 
thetic symptoms,  and  the  treatment  will  be  directed  to  the 
brain.  In  these  varieties  judicious  physicians  will  regard 
all  these  phenomena  in  a general  manner  j they  will  see 
in  all  a proof  of  that  general  agreement  which  disposes 
together  all  the  functions,  which  connects  all  and  thus 
connects  their  derangements  ; they  will  see  each  organ 
rise  up,  as  it  were  against  the  evil  which  is  introduced 
into  the  economy,  and  each  react  in  its  own  way  ; they 
will  see  these  reactions  producing  effects  wholly  different, 
according  to  the  organ  reacting,  fever  arising  from  the 
reaction  of  the  heart,  delirium,  drowsiness,  watchfulness, 
convulsions,  &c.  from  that  of  the  brain,  vomiting  from 
that  of  the  stomach,  diarrhoea  from  that  of  the  intestines, 
gastric  and  intestinal  derangements,  foulness  of  the  tongue 
from  those  of  the  mucous  membranes,  overflowings  of 


44 


MUSCULAR  SYSTEM 


bile  from  that  of  the  liver,  &c.  Thus  in  a machine  irt 
which  the  whole  is  united  and  connected  together,  if  one 
part  is  deranged  all  the  others  are  so  also.  We  should 
laugh  at  the  mechanist  who  attempted  to  mend  but  one 
of  these  pieces,  and  neglected  to  repair  the  local  de- 
rangement from  which  all  those  arose  which  the  machine 
exhibits.  Let  us  not  laugh  at  the  physician  who  attacks 
only  a single  symptom,  without  combating  the  disease,  of 
which  he  oftentimes  knows  not  the  principle,  though  he 
knows  that  this  principle  exists ; but  let  us  laugh  at  him, 
if  he  attaches  to  his  treatment  an  importance  which  is 
nothing  compared  with  that  of  the  disease. 

The  intestines  next  to  the  stomach  are  the  most  often 
sympathetically  affected  in  diseases.  The  bladder  is  the 
organic  muscle  that  is  the  last  to  feel  the  influences  that 
go  from  the  diseased  organ  ; this  sometimes  however 
happens.  In  fevers,  we  know  that  retentions  of  urine 
from  sympathetic  and  temporary  paralysis,  are  not  very 
rare  ; incontinence  of  urine  is  less  often  seen. 

Character  of  the  Vital  Properties. 

We'  see  from  what  has  been  said,  that  the  vital  proper- 
ties are  very  active  in  the  organic  muscles,  especially  as 
it  respects  contractility.  These  muscles  are  really  during 
life,  in  constant  action  : they  receive  with  great  ease  the 
influence  of  other  organs.  Their  vital  properties  are  alter- 
ed with  the  greatest  promptness,  especially  that  which  I 
have  just  pointed  out ; for  the  insensible  contractility  is 
rarely  altered  in  them,  because  it  does  not  perform  an 
essential  part.  Observe  in  fact  that  the  morbid  derange- 
ments of  an  organ  affect  always  the  predominant  vital 
force  of  that  organ.  Animal  contractility  is  frequently 
altered  in  the  preceding  system  ; in  this  it  is  the  sensible 
organic  contractility.  On  the  contrary,  the  insensible 
being  very  small,  the  phenomena  over  which  it  presides 
remain  always  nearly  the  same ; nutrition  is  always  uni- 


OF  ORGANIC  LIFE. 


45 


form  ; lesions  of  the  muscular  texture  are  rare  ; -when 
they  take  place,  it  is  rather  by  communication,  as  in  can- 
cers of  the  stomach,  in  which  the  disease  begins  upon 
the  mucous  surface,  and  in  which  the  fleshy  fibres  are 
only  consequently  affected.  The  heart  and  the  womb  are 
the  muscles  that  are  the  most  subject  to  these  morbid 
alterations  ; yet  in  the  first  they  belong  oftener  to  the  in- 
ternal membrane  than  to  the  fleshy  fibres  themselves. 
On  the  contrary  in  the  systems  in  which  the  sensible  or- 
ganic contractility  is  incessantly  in  action,  as  in  the  cuta- 
neous, the  serous,  &c.  in  which  it  presides  over  nutrition 
and  exhalation ; in  the  glandular,  the  mucous,  &c.  in 
which  it  produces  secretion  and  nutrition,  it  is  this  which 
is  especially  altered.  From  these  derangements  arise 
alterations  of  texture,  organic  diseases  properly  called, 
which  are  as  common  in  these  systems,  as  they  are  rare 
in  those  in  which  the  insensible  contractility,  is  so  very 
obscure,  as  to  be  only  at  the  degree  necessary  for  nutri- 
tion. 

It  is  to  this  that  must  be  referred  the  infrequency  of 
acute  inflammations  of  this  system.  As  this  affection  is 
frequent  in  the  cutaneous,  the  serous,  the  mucous  systems, 
&c.  so  this  system,  whose  functions  require  but  little  in- 
sensible organic  contractility,  presents  it  rarely.  Those 
who  open  many  dead  bodies  know,  that  the  texture  of 
the  heart  is  hardly  ever  found  inflamed.  Nothing  is 
more  common  than  phlegmasia  of  the  external  or  serous 
membrane,  and  of  the  internal  or  mucous  membrane  of 
the  stomach,  the  intestines,  &c. ; but  nothing  is  more  ob- 
scure and  less  frequently  seen  than  that  of  their  fleshy 
tunic.  In  rheumatism,  there  is  sometimes  when  the  pains 
cease  around  the  joints,  violent  cholics,'  spasmodic  vomit- 
ings even,  indices  perhaps  of  an  acute  affection  of  the 
fibres  of  the  stomach  or  intestines;  but  we  never  find 
marks  of  these  affections ; we  do  not  see  the  muscular 
texture  exhibiting  the  bright  red  of  the  inflamed  mucous. 


46 


MUSCULAR  SYSTEM 


cutaneous  and  serous  organs ; or  at  least  I have  never 
observed  it. 

Physicians  have  not  paid  sufficient  attention  to  the  dif- 
ference of  inflammations  according  to  the  difference  of 
systems  ; but  especially  they  have  not  sufficiently  observ- 
ed that  this  difference  accords  perfectly  with  that  of  the 
insensible  organic  contractility ; that  where  this  vital 
force  is  most  characterized,  inflammations  have  the  great- 
est tendency  to  take  place,  because  it  is  this  which  pre- 
sides over  their  formation  ; because  these  affections  sup- 
pose its  increase ; as  convulsions  suppose  the  increase  of 
animal  contractility,  as  vomitings,  accelerated  pulsations 
of  the  heart,  suppose  that  of  organic  contractility,  &c.  I 
cannot  repeat  it  too  much,  that  the  most  frequent  diseases 
in  each  system,  put  always  in  action,  raise  or  diminish 
fhe  predominant  vital  force  in  that  system.  It  is  a new 
pathological  view,  that  may  be  fruitful  in  results. 


ARTICLE  FOURTH. 

PHENOMENA  OP  THE  ACTION  OP  THE  MUSCULAK  SYSTEM 
OP  ORGANIC  LIPE. 

These  phenomena  are,  as  in  the  preceding  system,  rela- 
tive to  the  state  of  contraction  or  to  that  of  relaxation. 

I.  Force  of  the  Contractions. 

It  is  never  capable  of  being  raised  to  the  point  which 
the  force  of  the  muscles  of  animal  life  sometimes  attains. 
Between  the  strongest  and  the  weakest  pulse,  between 


OF  ORGANIC  LIFE. 


47 


the  feeble  jet  which  precedes  some  retentions  of  urine, 
and  the  jet  of  the  most  vigorous  man,  there  is  much  less 
difference  than  between  the  langour  of  the  voluntary 
muscles  of  some  women  and  the  power  of  those  of  a 
maniac,  or  a man  in  anger.  The  heart  and  the  deltoid 
muscle  are  nearly  equal  in  respect  to  their  fleshy  mass ; 
now  what  would  become  of  the  circulation,  if  the  first 
sometimes  sent  the  blood  with  the  force  which  the  second 
uses  to  raise  the  superior  extremity  ? A fit  of  anger, 
mania,  &c.  is  sufficient  to  produce  aneurisms.  On  the 
other  hand  the  organic  muscles  are  not  affected  with  those 
prostrations  of  forces  so  common  in  the  others ; paralysis- 
is  foreign  to  them,  because  they  are  not  within  the  cerebral 
influence.  There  is  something  which  answers  to  convul- 
sions ; it  is  the  irregular  agitations  which  produce  so 
many  varieties  in  the  pulse  of  acute  fevers,  agitations 
which  must  be  distinguished  from  those  produced  by  an 
organic  defect  of  the  heart ; but  these  agitations  are 
wholly  different  from  spasms  of  the  voluntary  muscles  j 
there  is  even  no  analogy. 

There  is  not  in  the  force  of  the  contraction  of  the  mus- 
cles of  which  we  are  treating,  the  waste  which  is  so  re- 
markable in  that  of  the  other  muscles  ; the  effort  is  nearly 
proportionable  to  the  acting  cause,  and  the  distinction  of 
this  force  into  absolute  and  effective,  cannot  be  applied 
here  ; only  there  is  required  more  or  less  contractile 
energy,  according  as  the  body  to  be  expelled  from  a hol- 
low muscle,  is  solid  or  fluid.  Hence  why  the  great  in- 
testines are  provided  with  longitudinal  fibres  more  charac- 
terized than  those  of  the  small  intestines  ; why  the  rec- 
tum especially,  in  which  the  excrements  have  their  great- 
est degree  of  solidity,  exhibits  these  fibres  in  a more 
evident  manner  than  the  colon  or  the  caecum,  though 
under  a different  form  ; why  in  diarrhoeas  the  weakest 
contraction  is  sufficient  to  evacuate  the  intestines,  whilst 
the  sensible  organic  contractility  of  the  rectum  being  in- 


4S 


MUSCULAR  SYSTEM 


sufficient  to  void  very  solid  excrements,  it  is  necessary 
that  the  abdominal  muscle  should  aid  the  expulsion  ; why 
when  a hard  body  is  introduced  into  the  stomach,  and  the 
gastric  juices  do  not  soften  it,  it  remains  there  a long 
lime  before  being  expelled,  and  produces  an  inconvenient 
weight,  &c.  &c.  We  know  with  what  rapidity  the  pas- 
sage of  liquids  takes  place  from  the  stomach  to  the  intes- 
tines, and  how  long  on  the  contrary  solid  aliments  remain 
in  the  first. 

The  force  of  the  organic  muscles  is  incomparably 
greater  in  the  phenomena  of  life  than  in  our  experiments. 
Once  laid  bare,  the  heart  communicates  only  feeble  motions, 
and  most  often  irregular  ones.  There  is  no  proportion 
between  the  force  necessary  to  produce  the  jet,  some- 
times from  seven  to  eight  feet,  which  the  blood  exhibits 
coming  from  the  open  carotid  of  a dog,  and  the  force  of 
the  contractions  which  the  strongest  stimuli  produce  when 
applied  to  the  heart  extracted  from  the  body.  Nothing 
equals  in  our  experiments  the  force  of  contraction  neces- 
sary for  vomiting,  &c.  &c. 

Numerous  calculations  have  been  made  upon  the  force 
of  contraction,  in  the  organic  muscles  as  in  the  preceding, 
and  there  Jias  been  the  same  variety  of  results.  Can  we 
in  fact  calculate  the  degrees  of  a phenomenon  which 
a thousand  causes  make  vary  every  instant,  not  only  in 
different  individuals,  but  even  in  the  same,  which  sleep, 
digestion,  exercise,  rest,  tranquillity  of  mind,  violence  of 
the  passions,  day,  night,  every  thing  in  a word,  incessantly 
mo'difies  ? I do  not  know  that  we  digest  twice  in  exactly 
the  same  period,  if  the  urine  twice  remains  the  same 
length  of  time  in  the  bladder,before  being  discharged,  if 
its  jet  is  twice  exactly  equal,  &c. 

The  force  of  the  organic  muscles  often  remains  in  its 
ordinary  degree,  or  is  even  increased  ; whilst  a general 
weakness  possesses  the  others.  The  force  of  the  pulse, 
vomiting,  diarrhoea,  &c.  coinciding  with  a general  pros- 


OF  ORGANIC  LIFE. 


49 


iration  of  the  muscles  of  animal  life,  are  not  rare  phenom- 
ena in  diseases. 

II.  Quickness  of  the  Contractions. 

It  varies  singularly ; very  rapid  in  experiments,  when 
death  is  recent  and  the  stimuli  are  very  strong,  the  con- 
tractions are  in  general  slower  in  the  natural  state;  we 
might  say  that  it  is  in  the  inverse  ratio  of  the  force ; often 
at  the  instant  we  open  the  pericardium,  the  heart  moves 
with  a rapidity  which  the  eye  can  hardly  follow,  espe- 
cially if  we  inject  an  irritating  fluid  into  this  serous  sac, 
a little  before  laying  the  organ  bare.  The  contractions 
increase  much  in  quickness  in  certain  diseases ; those  of 
the  heart,  for  example,  then  acquire  in  the  adult  a rapidity 
often  much  greater  than  they  have  in  the  first  age  ; this 
rapidity  is  also  in  this  case  entirely  distinct  from  the  force 
of  its  contractions  ; it  is  rare  even  that  these  two  things 
are  found  united  at  the  highest  point.  In  general  when 
the  force  of  the  heart  is  increased,  there  is  a little  more 
quickness  ; but  there  is  very  often  a dimunition  of  force 
with  an  increase  of  quickness,  or  the  force  remains  the 
same,  the  quickness  being  much  increased. 

We  have  seen  that  the  voluntary  muscles  have  in  gen- 
eral a degree  of  quickness  beyond  which  they  cannot  go, 
and  that  this  quickness  belongs  to  the  original  constitution. 
Is  not  the  same  phenomenon  observed  here  ? Often  in 
two  fevers  whose  symptoms  are  the  same,  whose  degree 
of  intensit)?-  seems  to  be  exactly  uniform,  the  pulse  is  infi- 
nitely more  frequent  in  one  individual  than  in  the  other. 
This  does  not  always  denote  a difierence  in  the  disease, 
but  in  the  primitive  constitution,  an  aptitude  of  one  of 
the  two  hearts  to  contract  much  quicker  under  the  same 
stimulant.  Who  does  not  know  that  in  experiments,  the 
contractile  rapidity  is  infinitely  variable  under  the  influ- 
ence of  the  same  causes  ? 

7 


VOL.  III. 


50 


MUSCULAR  SYSTEM. 


Each  organic  muscle  has  its  degree  of  quickness  ; the 
heart,  the  stomach,  the  intestines,  the  bladder,  &c.  differ 
remarkably  in  this  respect. 

III.  Duration  of  the  Contractions. 

The  heart  never  remains  in  permanent  contraction,  as 
often  happens  in  the  voluntary  muscles.  Though  hunger 
seems  to  prove  the  contrary  in  the  stomach  and  the  intes- 
tines, yet  this  phenomenon  is  not  contradictory ; in  fact, 
the  permanent  contraction  of  the  empty  gastric  viscera  is 
the  result  of  the  contractility  of  texture.  Whenever  the 
sensible  organic  contractility  is  in  action,  there  is  alter- 
nate contraction  and  dilatation  ; this  alternation  even  cha- 
racterizes essentially  this  last  property,  and  distinguishes 
it  from  the  animal  contractility  and  from  that  of  texture, 
in  which  the  state  of  contraction  is  often  permanent. 

IV.  State  of  the  Muscle  in  Contraction. 

All  the  phenomena  described  for  the  voluntary  mus- 
cles, are  almost  applicable  to  these,  such  as  the  hardening, 
increase  in  thickness,  diminution  in  length,  expression  of 
the  blood,  &c.  &c.  But  there  are  some  differences  be- 
tween the  heart  and  the  gastric  muscles,  in  respect  to  the 
mode  of  contraction.  In  fact  we  see  veiy  sensibly  in  the 
first,  1st,  contractions  of  the  w'hole  analogous  to  those  of 
the  voluntaiy  muscles,  contractions  which  take  place  in 
the  state  of  health,  which  produce  the  projection  of  the 
blood,  and  which  are  easily  made  in  experiments  when 
the  animals  are  still  living ; 2d,  numerous  oscillations 
which  seize  upon  the  fibres,  w’hich  agitate  the  whole  of 
them  without  producing  any  sensible  effect,  without  con- 
tracting the  cavity,  without  projecting  the  blood  for  ex- 
ample. These  oscillations  are  ci^gerved  at  the  instant  of 
death,  when  the  heart  is  ceasing  to  be  contractile  ; we 
may  then  irritate  it  in  vain,  thei’e  are  no  more  contrac- 


OF  ORGANIC  LIFE. 


51 


tions  of  it  as  a whole  ; though  there  is  a general  and  very- 
evident  vibration  of  its  fibres,  yet  its  cavity  is  not  con- 
tracted ; the  blood  stagnates  in  it.  The  heart  perfectly 
resembles  under  this  double  relation  the  voluntary  mus- 
cles ; it  is  agitated  as  we  see  these  muscles  in  the  shud- 
dering, that  is  called  horripilatio,  as  we  see  it  also  in  cer- 
tain suh-cutaneous  muscles  in  some  individuals.  I have 
already,  for  example,  seen  many  persons  affected  with  an 
habitual  trembling  of  a portion  of  the  solseus,  a trembling- 
very  evident  to  the  eye  through  the  skin,  and  which  had 
nothing  in  common  with  the  contraction  necessary  to  the 
extension  of  the  foot. 

The  involuntary  muscles  of  the  abdomen  never  exhibit 
this  double  mode  of  contraction.  Instead  of  the  quick 
and  sudden  motions  of  the  whole  of  the  muscle,  we  see 
but  a slow  contraction  in  it,  often  but  slightly  apparent'; 
it  is  a kind  of  creeping  ; there  is  not  even  to  speak  pro- 
perly a contraction  of  the  whole,  like  that  of  the  heart 
in  which  all  the  fibres  of  an  auricle  or  ventricle  are  moved 
at  the  same  time ; here  each  fleshy  surface  appears  to  act 
successively.  Placed  at  the  origin  of  the  great  vessels, 
the  bladder  and  the  stomach  would  be  incapable  of  com- 
municating to  the  blood  those  motions  by  jerks,  which 
the'  jet  of  an  artery  exhibits  at  each  contraction.  On  the 
other  hand,  at  the  instant  the  motion  ends  in  the  stomach, 
the  intestines  and  the  bladder,  we  never  see  in  them 
those  oscillations,  those  vibrations  which  are  almost  con- 
stant in  the  heart  and  the  voluntary  muscles,  and  which 
we  can  even  create  in  them  at  will. 

V.  Motions  imparted  by  the  Organic  Muscles. 

There  are  hardly  ever  simple  motions  in  these  muscles  ; 
the  different  interlacing  of  their  fleshy  surface  allows  them 
to  act  almost  always  in  three  or  four  different  directions 
upon  the  substances  they  contain.  We  can  say  nothing 


I 


52  MUSCULAR  SYSTEM 

general  upon  those  motions  which  compose  the  diastole 
of  the  heart,  the  peristaltic  motion  of  the  alimentary  canal, 
the  contraction  of  the  bladder,  &c.  Each  muscle  has  its 
mechanism  which  belongs  to  the  physiological  history  of 
the  function  to  which  it  contributes. 

VI.  Phenomena  of  the  Relaxation  of  the  Organic 
Muscles. 

In  the  relaxation  of  the  organic  muscles,  phenomena  in 
general  take  place  that  are  opposite  to  the  preceding.  It 
is  then  useless  to  enumerate  them  ; but  there  is  a question 
here  that  should  be  examined,  that  of  knowing  the  nature 
of  that  state  which  succeeds  contraction  and  alternates 
with  it. 

In  the  muscles  of  animal  life,  when  the  contraction 
ceases,  the  muscle  does  not  in  general  go  back  itself  to 
the  state  it  was  in  antecedent  to  the  contraction,  but  it  is 
drawn  back  to  it  by  its  antagonist ; for  example,  when 
the  biceps  is  contracted  to  bend  the  fore-arm  and  its  con- 
traction ceases,  it  becomes  passive ; the  triceps  putting 
itself  then  in  motion,  extends  it  and  draws  it  back  to  its 
natural  position,  by  acting  at  first  on  the  bones  which 
communicate  the  motion  to  this  muscle.  Each  muscular 
power  of  animal  life  finds  then  in  that  which  is  opposed 
to  it  a cause  of  return  to  the  state  it  had  left  in  order  to 
contract.  It  is  not  so  in  organic  life  ; its  muscles,  which 
are  all  hollow,  have  no  antagonists.  We  have  considered 
as  such  to  a certain  extent,  the  substances  contained  in 
the  hollow  muscles,  substances  which  oppose  the  effect  of 
contraction  ; but  incapable  most  commonly  of  reacting 
after  having  been  compressed,  on  account  of  their  want 
of  elasticity,  these  substances  cannot  perform  the  same 
offices  as  real  antagonists. 

Most  physiologists  have  admitted  as  a cause  of  dilata- 
tion, the  entrance  of  new  substances,  which  replace,  in 
the  muscular  cavities,  those  expelled  by  contraction  ; thus 


OF  ORGANIC  LIFE. 


53 


the  entrance  of  new  blood  into  the  heart,  aliments  into 
the  different  portions  of  the  alimentary  canal,  has  been 
considered  as  proper  to  dilate  these  organs  ; so  that  ac- 
cording to  this  opinion  the  muscles  would  be  purely 
passive  when  they  enlarged.  But  the  following  consider- 
ations, many  of  which  some  authors,  Grimaud  in  particu- 
lar, have  already  stated,  do  not  permit  us  to  consider  in 
this  way  the  dilatation  of  the  organic  muscles,  that  of  the 
heart  in  particular. 

1st.  When  we  lay  bare  a hollow  muscle,  the  heart,  the 
stomach,  or  the  intestines,  and  empty  it  entirely  of  the  sub- 
stances that  it  contains,  it  contracts  and  dilates  alternately 
as  when  it  is  full,  if  we  apply  an  external  stimulant  to  it. 
2d.  If  we  empty  by  punctures  all  the  great  vessels  which 
go  to  the  heart,  or  come  from  it,  so  as  to  evacuate  it  en- 
tirely, its  alternate  dilatations  and  contractions  continue 
for  some  time.  3d.  In  order  to  judge  comparatively  of 
the  degree  of  force  of  the  contraction  and  the  dilatation, 
we  can  extract  two  hearts  nearly  equal  in  size  from  two 
living  animals  ; place  immediately  the  fingers  of  one  hand 
into  the  auricles  or  the  ventricles  of  the  first,  and  grasp 
with  the  other  hand  the  exterior  of  the  second  j you  will 
feel  that  one  makes  as  great  an  effort  in  dilating  as  the  other 
does  in  contracting.  This  fact  already  observed  by  Pech- 
lin,  is  so  much  the  more  remarkable,  as  the  effort  of  dila- 
tation is  often  greater  than  that  of  contraction.  I have 
even  observed,  in  repeating  this  experiment,  that  what- 
ever effort  we  make  with  the  hand,  we  cannot  prevent 
the  organ  from  dilating.  4th.  The  alternate  extension  and 
contraction,  from  which  arises  the  vermicular  motion  of 
the  intestines,  is  seen  during  hunger  when  we  open  the 
abdomen  of  an  animal.  5th.  The  hardness  of  the  or- 
ganic muscular  texture  is  as  evident  during  dilatation  as 
during  vacuity.  6th.  I have  many  times  observed  that 
at  the  instant  in  which  I irritated  the  heart  with  the  point 
of  a scalpel,  that  a dilatatio^n  was  the  first  consequence  o 


54 


MUSCULAR  SYSTEM 


it,  and  that  contraction  was  only  consequent  to  it.  It 
liappens  in  general  more  often  that  contraction  begins  the 
motions  in  our  experiments  ; but  certainly,  the  muscle 
being  at  rest,  it  is  frequently  a dilatation  that  first  mani- 
fests itself. 

It  appears  then  very  probable  that  the  dilatation  of  the 
organic  muscles  is  a phenomenon  as  vital  as  their  con- 
traction ; that  these  two  states  are  united  in  a necessary 
manner;  that  both  of  them  compose  muscular  motion,  of 
which  contraction  is  but  one  part.  Who  knows  even  if 
each  may  not  be  disturbed  separately,  if  to  a regular  con- 
traction may  not  succeed  an  irregular  dilatation  and  vice 
versa  ? Who  knows  if  certain  alterations  in  the  pulse  do 
not  belong  to  injuries  of  dilatation  and  others  to  those  of 
contraction  ? I am  far  from  being  certain  ; for  in  medi- 
cine we  must  rest  our  belief  on  certainty  and  not  on  pre- 
sumption ; but  we  can  make  this  point  an  object  of  re- 
search. 

It  appears  that  sometimes  the  voluntary  muscles  are 
also  the  seat  of  a true  active  dilatation.  1st.  A muscle, 
laid  bare  and  extracted  from  the  body,  contracts  and  after- 
wards dilates,  without  being  drawn  to  this  state  of  dilata- 
tion by  any  cause.  2d.  In  an  amputation,  we  often  see 
in  the  stump  the  end  of  the  divided  fibres  alternately 
lengthen  and  contract ; a double  motion  both  of  which 
appears  to  be  equally  vital.  3d.  In  many  kinds  of  con- 
vulsions in  which  the  extremities  stiffen,  in  those,  for  ex- 
aniple,  which  accompany  most  hysterical  fits,  it  appears 
that  there  is  a veiy  evident  active  dilatation  ; by  placing 
in  fact  the  hand  upon  the  muscles  which  should  then  be 
) elaxed,  from  the  disposition  of  the  parts,  we  perceive  a 
hardness  as  great  as  in  feeling  of  the  contracted  muscles. 

There  are  many  researches  to  be  made  upon  this  mocio 
of  dilatation  of  our  parts,  a mode  which  undoubtedly  is 
not  exclusively  confined  to  the  muscular  system,  but 
which  appears  to  belong  also  to  the  iris,  to  the  spongy 


OF  ORGANIC  LIFE, 


55 


texture  of  the  corpora  cavernosa,  to  the  nipples,  &c.  All 
these  organs  move  by  dilating  very  evidently ; contrac- 
tion succeeds  in  them  expansion,  as  in  the  common  mus- 
cles relaxation  does  contraction.  Expansion  is  the  prin- 
cipal phenomenon.  Perhaps  also,  as  some  modern  authors 
have  thought,  the  sudden  swellings  of  the  cellular  texture, 
which  accompany  contusions,  bruises,  &c.  are  the  result 
of  this,  mode  of  motion. 


DEVELOPMENT  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC 
- LIFE. 

The  organic  muscular  system  is  wholly  the  reverse  of 
the  preceding,  as  it  respects  development.  This  is  but 
slightly  characterized  in  the  early  ages,  whereas  the 
growth  of  the  other  is  precocious.  Let  us  follow  it  in 
all  the  ages. 

^ "s. 

I.  State  of  the  Organic  Muscular  System  in  the 
Foetus. 

In  the  first  days  after  conception,  the  heart  is  formed ; 
it  is  the  first  point  of  motion,  a puuctum  saliens,  as  it  has 
been  called.  The  researches  of  different  authors,  of  Haller 
in  particular,  have  rendered  clear  the  successive  progress 
of  its  increase  in  the  early  periods.  Rather  late  in  their 
formation,  the  muscles  of  the  interior  of  the  abdomen  are 
yet  developed  before  those  that  form  the  parietes  of  this 


ARTICLE  FIF 


5G 


MUSCULAR  SYSTEM 


cavity.  It  is  the  size  of  the  intestines,  tlie  stomach,  tlie 
bladder,  &c.  almost  as  much  as  that  of  the  liver,  which 
gives  to  the  cavity  in  which  these  viscera  are  found,  the 
remarkable  capacity  that  it  then  exhibits. 

Nearly  uniform  at  this  age,  as  it  respects  the  propor- 
tion of  their  size,  all  the  organic  muscles  are  not  as  much 
so  in  regard  to  that  of  their  texture.  The  heart  is 
evidently  firmer  and  more  dense  than  all  the  others ; its 
texture  is  very  distinct.  The  fibres  of  the  stomach,  intes- 
tines and  bladder  are  soft  and  loose  and  resemble  exactly 
those  of  the  muscles  of  animal  life ; but  little  blood  goes 
to  them  in  proportion  to  what  they  are  afterwards  to  re- 
ceive. The  fibres  of  the  heart,  on  the  contrary,  dense 
and  compact,  have  a power  of  action  in  proportion  to 
what  they  are  afterwards  to  have.  Their  redness  is  as 
distinct ; as  much  blood  penetrates  and  consequently 
nourishes  them.  This  redness  of  the  heart,  analogous  in 
the  adult  to  that  of  the  voluntary  muscles,  forms  at  this 
period  a contrast  with  the  remarkable  paleness  of  these 
muscles.  Besides  it  has,  as  in  all  the  other  parts  where 
it  exists,  a deep  tinge,  owing  to  the  kind  of  blood  that 
produces  it. 

We  easily  see  the  reason  of  the  quantity  of  blood  that 
penetrates  the  heart,  as  this  organ  then  very  active  in  its 
motions,  has  need  of  much  force,  whilst  the  others,  almost 
immoveable,  require  but  little. 

Yet  the  sensible  organic  contractility  of  the  heart  in  the 
fetus  and  in  the  first  age  has  been  exaggerated,  undoubt- 
edly on  account  of  the  extreme  rapidity  that  the  circula- 
tion then  exhibits.  This  rapidity  depends  as  much  on 
the  activity  of  the  tonic  forces  of  the  general  capillary 
system,  as  on  that  of  the  heart;  for  the  blood,  when  it 
has  arrived  in  the  capillary  system,  is  wholly  beyond  the 
influence  of  the  heart,  as  we  have  seen  ; the  stay  that  it 
makes  there  is  wholly  dependant  upon  the  forces  of  the 
system  itself;  now  these  forces,  at  that  time  very  active, 


OF  ORGANIC  LIFE. 


57 


accelerate  the  course  of  the  blood,  and  send  it  into  the 
renous  system,  from  which  it  goes  to  the  heart.  If  the 
excitability  of  this  were  double  and  even  treble,  and  the 
blood  entered  it  but  slowly,  it  would  be  unable  to  support 
a rapid  and  at  the  same  time  continuous  pulse.  Haller 
was  drawn  to  this  opinion  by  believing  that  the  heart 
was  the  only  agent  of  impulse  of  the  blood  circulating 
even  in  the  small  vessels.  Besides,  there  is  no  doubt 
that  the  sensible  organic  contractility  of  the  heart  is  less 
easily  put  into  action  by  experiments  in  the  foetus,  and 
that  it  is  also  much  less  durable.  Then  the  strongest 
stimuli  have  less  effect  upon  it  an  instant  after  death,  than 
those  of  less  power  exhibit  upon  the  heart  of  an  animal 
that  has  been  born.  I have  many  times  established  this 
fact  upon  foetuses  of  guinea-pigs.  Compared  with  that  of 
the  voluntary  muscles,  the  mobility  of  the  heart  is  un- 
doubtedly remarkable  in  the  foetus  ; but  compared  to  what 
it  will  be  after  birth,  it  is  but  slight. 

It  is  precisely  the  same  with  the  contractility  of  the 
stomach,  the  bladder  and  the  intestines  ; most  commonly 
we  can  produce  no  motion  in  these  muscles  by  stimuli. 
Mr.  Leveille  has  already  made  these  important  observa- 
tions ; he  has  also  remarked  that  the  urine  remained  in 
the  bladder,  and  the  meconium  in  the  great  intestines, 
without  producing  a contraction  sufficient  to  expel  them. 
I do  not  think  however  that  there  could  be  during  life  a 
complete  immobility  of  the  gastric  viscera,  and  for  this  rea- 
son ; most  commonly  the  meconium  is  only  met  with  in  the 
great  intestines ; it  must  have  been  formed  in  them  then, 
if  there  was  complete  immobility  of  the  gastric  muscles ; 
now  it  is  much  more  probable  that  it  is  the  residuum  of  the 
bile,  of  all  the  mucous  juices,  &c. ; that  consequently  it 
has  been  pushed  successively  by  a slow  action  from  the 
superior  part  towards  the  inferior  of  the  alimentary  canal. 

The  softness  of  the  organic  muscles  renders  their  exten- 
sibility of  texture  very  great  at  this  period.  I would 
VOL.  in.  8 


58 


MUSCULAR  SYSTEM 


observe  however  that  the  hearts  of  dead  foetuses  do  not 
exhibit  those  numberless  varieties  of  size  which  those  of 
adults  do  in  the  right  side,  according  to  the  different 
kinds  of  death. 

II.  State  of  the  Organic  Muscular  System  during 
Growth. 

The  first  days  of  existence  are  marked  by  an  internal 
motion  as  quick  in  manifesting  itself  as  the  external  of 
which  we  have  sjjoken.  The  sucking  of  the  milk,  the 
evacuation  of  the  urine  and  meconium,  &c.  are  indices  of 
this  general  internal  motion,  of  this  agitation  almost  sud- 
den of  all  the  involuntary  muscles. 

It  is  not  the  brain  which,  entering  into  action  at  birth, 
produces  the  contraction  of  these  muscles,  since  as  we 
have  said  they  are  not  under  its  government ; it  appears 
to  depend,  1st,  on  the  sympathetic  influence  exerted 
upon  their  system,  by  the  cutaneous  organ,  which  is  irri- 
tated by  the  new  medium ; 2d,  on  the  excitement  made 
upon  the  beginning  of  all  the  mucous  surfaces,  and  upon 
the  whole  of  that  of  the  lungs,  an  excitement  which  af- 
terwards reacts  upon  these  muscles  ; 3d,  on  that  produced 
by  fluids  introduced  into  the  stomach  •,  4th,  on  the  sud- 
den entrance  of  the  red  blood  into  all  these  muscles,  till 
then  penetrated  like  the  others  with  black ; this  cause  is 
essential ; irritability  appears  to  be  in  part  dependant  on 
it,  or  at  least  to  borrow  from  it  a remarkable  increase  of 
force  ; 5th,  the  excretion  of  the  meconium  and  the  urine 
is  also  powerfully  assisted  by  the  abdominal  muscles, 
which  then  enter  into  activity  with  the  whole  system  to 
which  they  belong. 

The  general  internal  motion  which  takes  place  in  the 
first  moments  of  existence,  and  which  is  produced  by  the 
suddenly  increased  activity  of  the  involuntary  muscles, 
has  an  important  use  with  respect  to  the  mucous  surfaces, 
which  it  relieves  of  the  fluids  that  load  them,  and  whose 


OF  ORGANIC  LIFE, 


59 


presence  becomes  painfnl.  Where  the  mucous  surfaces 
have  not  around  them  fleshy  layers  of  the  involuntary 
muscles,  as  in  the  bronchia,  the  nasal  fossae,  &c.  the  mus- 
cles of  animal  life  more  or  less  distant,  perform  this  func- 
tion, as  for  example,  the  diaphragm  and  the  intercostals, 
free  the  bronchial  surface  by  coughing,  and  the  pituitary 
by  sneezing. 

As  we  recede  from  the  period  of  birth,  the  organic 
muscles  grow  in  general  much  less  in  proportion  than 
the  others  ; it  is  this  that  gradually  re-establishes  the  equi- 
librium between  the  two  systems.  I would  remark  how- 
ever, as  it  respects  the  predominance  of  the  first,  that  it 
is  much  less  conspicuous  in  the  foetus  than  that  of  the 
nervous  system.  The  brain,  for  example,  is  in  propor- 
tion much  larger  than  the  heart. 

It  is  probable  that  the  muscles  of  which  we  are  treat- 
ing, exhibit,  at  this  period,  the  same  varieties  of  composi- 
tion as  the  others,  that  gelatine  especially  predominates  in 
them,  that  they  have  less  fibrin,  &c.  This  last  substance 
perhaps  exists,  in  the  early  periods,  more  abundantly  in 
the  heart  than  in  the  other  muscles  of  this  class. 

W’e  have  observed  two  very  distinct  periods  in  the 
growth  of  the  other  muscles ; one  is  finished  when  they 
have  acquired  their  length  ; the  other,  when  their  thick- 
ness is  complete.  The  first  has  not,  in  the  organic  sys- 
tem, a term  as  distinct;  when  the  stature  no  longer  in- 
creases, the  gastric  and  urinary  organs,  and  the  heart  Still 
lengthen  and  grow. 

We  have  considered  growth  in  too  general  a manner. 
Each  system  has  a difierent  term  in  this  great  phenome- 
non. The  osseous  and  muscular  systems  of  animal  life, 
and  those  which  depend  on  them,  as  the  fibrous,  the  car- 
tilaginous, &c.  have  especially  an  influence  upon  the  gen- 
eral stature  of  the  body  ; it  is  these  which  produce  this 
or  that  height ; but  this  height  has  no  influence  upon  the 
length  of  the  intestines,  or  the  capacity  of  the  stomach, 


60 


MUSCULAR  SYSTEM 


the  heart,  the  bladder,  &c.  The  glandular,  serous,  mucous 
systems,  &c.  are  equally  independent  of  stature  ; thus  in 
these  numerous  varieties,  it  has  much  more  influence 
upon  the  extremities,  than  upon  the  abdomen,  the  tho- 
rax, &c.  A great  height  indicates  the  predominance  of 
the  apparatus  of  locomotion,  but  not  of  those  of  diges- 
on,  respiration,  &c.  The  termination  of  the  growth  in 
height,  which  we  consider  in  a general  manner  for  the 
whole  body,  is  only  the  termination  of  the  growth  of  the 
muscles,  the  bones  and  their  dependancies,  and  not  of 
that  of  the  internal  viscera,  which  still  lengthen  and  be- 
come thicker.  It  is  easy  to  be  convinced  of  this,  by 
comparing  the  organic  muscles  of  a young  man  of  eighteen 
years,  with  those  of  a man  of  thirty  or  forty. 

The  organic  muscles  do  not  appear  to  be  subject  to 
those  irregularities  of  growth  which  the  other  muscles 
and  the  bones  frequently  exhibit.  We  know  that  the 
stature  often  remains  stationary  for  many  years,  and  that 
suddenly  it  acquires  very  great  dimensions  in  a very  short 
time  ; this  phenomenon  is  remarkable  especially  after  long 
diseases.  Now  notwithstanding  these  inequalities,  the 
heart  and  all  the  other  analogous  muscles  grow  in  an  uni- 
form manner ; the  regularity  of  the  internal  functions  to 
which  these  muscles  especially  contribute,  could  not 
adapt  itself  to  those  aberrations  which  would  be  unable  to 
disturb  the  functions  of  the  locomotive  organs.  Besides, 
if  they  took  place,  the  circulation,  digestion,  excretion  of 
urine,  &c.  would  exhibit  corresponding  aberrations ; now 
this  is  never  observed.  The  heart  and  the  gastric  mus- 
cles, &c.  always  grow  in  an  infant  whose  stature  remains 
stationary  ; they  do  not  grow  suddenly  in  one  who  grows 
at  once ; hence  why  the  thorax  and  the  abdomen  become 
large  in  the  first  case,  and  remain  contracted  in  the  second 
in  proportion  to  the  extremities. 

Besides  these  two  systems  are  never  in  precise  relation 
of  nutrition  and  power.  I have  already  observed  that 


t 


OF  ORGANIC  LIFE. 


61 


very  large  organic  muscles  often  exist  with  very  small 
voluntary  ones,  and  vice  versa. 

Let  us  consider  neither  the  growth  nor  nutrition  in  an 
uniform  manner  ; each  system  is  developed  and  increases 
in  its  own  way  ; all  are  never  found  at  the  same  periods  of 
this  function.  Why  ? because  nutrition,  like  all  the  other 
acts  over  which  life  presides,  is  essentially  dependant  on 
the  vital  forces,  and  these  forces  vary  in  each  system. 

The  growth  of  the  involuntary  muscular  system  is  not 
uniform  in  all  the  organs  which  compose  it.  Each  in- 
creases more  or  less,  or  is  differently  developed  ; one  often 
predominates  over  the  others  in  an  evident  manner;  a 
bladder  with  strong,  fleshy  fibres,  with  columns  as  they 
are  called,  is  often  found  in  a subject  with  a debilitated 
stomach,  with  small  intestines,  &c.  ; reciprocally,  the 
stomach,  the  heart,  &c.  have  often  an  insulated  predomi- 
nance. 

III.  State  of  the  Organic  Muscular  System  after 
Growth. 

I 

It  is  from  the  twenty-fourth  to  the  twenty-sixth  year, 
that  the  organic  muscles  are  completely  developed.  Then 
the  thorax  and  the  abdomen  which  contain  them  have 
their  greatest  capacity.  These  muscles  are  then  as  they 
are  to  remain  through  life  ; they  have  a density  much 
greater  than  in  youth  ; their  power  is  increased  and  their 
colour  is  deeper.  In  general  this  is  subject  in  the  heart 
to  frequent  varieties,  which  coincide  very  nearly  with 
the  varieties  of  the  preceding  system.  Acute  and  chronic 
diseases  have  nearly  the  same  influence  upon  it.  It  is 
equally  the  index  of  the  sanguineous,  lymphatic  temper- 
aments, &c.  by  the  different  tinge  it  assumes.  The  colour 
of  the  gastric,  intestinal  and  vesical  fibres  varies  less ; 
their  whiteness,  more  uniform,  is  rarely  influenced  by 
diseases. 


62 


MUSCULAR  SYSTEM 


We  cannot  increase,  by  constant  exercise,  the  nutrition 
of  the  organic  muscles.  Aliments  taken  beyond  measure, 
making  the  stomach  frequently  contract,  weaken  it  instead 
of  developing  its  fibres  more,  as  happens  from  constant 
exercise  given  to  a superior  or  inferior  extremity.  The 
bladder  incessantly  in  action  in  some  cases  of  inconti- 
nence, is  thus  gradually  weakened  and  loses  its  energy. 
We  might  say  that  these  two  systems  were  in  this  respect 
in  an  inverse  order. 

It  appears  that  the  nutrition  of  the  organic  muscles, 
like  that  of  the  others,  is  subject  to  frequent  variations  ; 
that  at  some  periods  they  are  more  developed  and  less  so 
at  others.  Diseases  have  a great  influence  upon  this  phe- 
nomenon, which  proves,  like  the  softening  of  the  bones 
and  their  return  to  the  natural  state,  the  constant  compo- 
sition and  decomposition  of  which  these  organs  are  the 
seat.  We  find  in  the  dissecting  rooms  many  differences 
in  different  subjects,  as  it  respects  the  colour,  density  and 
cohesion  of  the  muscles.  Now  what  many  exhibit  then 
at  once,  the  same  individual  often  experiences  succes- 
sively; the  same  man  no  doubt  has,  according  to  the  dif- 
ferent influences  to  which  he  is  exposed,  his  heart  red, 
dense,  large  and  well  nourished  at  one  period  of  life,  and 
feeble,  pale  and  small  at  another ; for  the  internal  organs 
experience  the  same  alterations  as  the  exterior.  Now  we 
know  that  the  external  appearance  often  changes  during 
life. 

IV.  Siate  of  the  Organic  Muscular  System  in  Old 
Jige. 

As  we  advance  in  age,  the  muscular  system  of  which 
Ave  are  treating  becomes  weak  like  all  the  others  ; yet  its 
action  is  more  durable  ; it  survives,  if  we  may  so  say, 
that  of  the  other.  When  the  old  man,  almost  immove- 
able, crawls  about  but  slowly  and  with  pain,  his  pulse, 
digestion,  &c.  have  vigour  still.  This  difference  of  the 


OF  ORGANIC  LIFE. 


63 


two  systems  is  so  much  the  more  remarkable,  as  the  time 
of  activity  of  the  second  is  almost  by  half  less  than  that 
of  the  first ; sleep  cuts  off  in  fact  almost  half  of  the  du- 
ration of  the  voluntary  motions,  whilst  it  leaves  the  in- 
voluntary wholly  untouched.  This  phenomenon  of  the 
organic  muscles  as  it  were  surviving  the  voluntary  in  the 
last  periods  of  life,  is  derived  on  a great  scale  from  the 
same  principle  from  which  arises  on  a small  one  the  lassi- 
tude which  follows  the  contraction  in  an  insulated  motion. 
A less  durable  motion  is  necessary  to  fatigue  the  volun 
tary  muscles,  than  to  fatigue  the  involuntary  ; the  stomach 
empty  remains  for  a long  time  contracted  upon  itself  with- 
out producing  any  painful  sensation,  whilst  if  we  hold  a 
body  strongly  grasped  between  our  fingers  for  a quarter 
of  an  hour,  all  the  flexors  are  soon  painfully  afiected. 
After  a convulsion  of  half  an  hour,  in  which  all  the  loco- 
motive muscles  have  been  stiff,  the  whole  body  is  broken, 
as  it  is  called  ; it  cannot  admit  of  any  motion ; whilst 
after  a paroxysm  of  fever  of  six  or  eight  hours  in  which 
the  pulse  has  been  violently  agitated,  the  heart  often  pre- 
serves the  natural  type  of  its  contractions ; it  requires 
repeated  paroxysms  to  weaken  it.  All  these  phenomena 
of  the  two  muscular  systems  evidently  prove  that  that  of 
animal  life  is  fatigued  much  the  soonest ; it  is  this  which 
occasions  its  intermission.  Is  it  then  astonishing  that, 
although  less  often  in  exercise  than  the  other,  it  exhausts 
sooner  the  quantum  of  force  nature  has  given  to  it  ? is  it 
astonishing  that  the  other  survives  the  longest  ? Life  is 
a great  exercise  which  gradually  wears  up  the  organs  in 
motion,  and  which  requires  their  rest ; this  rest  is  death  ; 
now  each  moveable  organ  arrives  at  it  sooner  or  later, 
according  to  the  different  degree  of  the  forces  which  it 
has  to  expend,  and  according  to  its  greater  or  less  dispo- 
sition to  be  weai’ied  by  this  great  exercise. 

Yet  the  organic  muscles  are  gradually  weakened.  The 
pulse  becomes  slower,  digestion  is  longer  in  old  age  5 the 


64 


MUSCULAR  SYSTEM 


bladder  and  rectum  first  cease  to  act ; then  the  intestines 
remain  inactive ; the  stomach  and  especially  the  heart  die 
the  last. 

A long  time  before  death,  the  muscular  cohesion  is 
weakened  in  this  system  as  in  the  preceding ; the  fleshy 
texture  becomes  flaccid  ; the  parietes  of  the  heart  support 
themselves  in  youth  ; they  flatten  in  old  age.  The  gas- 
tric system  of  a young  animal  suddenly  killed  during 
hunger  is  firm,  dense  and  contracted  upon  itself ; in  an 
old  one,  under  the  same  circumstance,  it  is  but  little 
contracted;  the  stomach  and  intestines  remain  much  more 
dilated ; they  are  loose  and  soft ; it  is  the  same  phenome- 
non as  in  the  preceding  muscles,  which  vacillate  under 
the  skin,  from  want  of  cohesion.  The  bladder  remains 
constantly  large,  though  empty. 


MUCOUS  SYSTEM, 


THIS  system,  the  name  of  which  I borrow  from  the 
fluid  that  constantly  lubricates  it,  and  which  is  furnished 
by  small  glands  inherent  in  its  structure,  appears  every- 
where in  a membranous  form  ; that  of  fasciculi  is  wholly 
foreign  to  it.  In  speaking  of  the  mucous  organs  we  shall 
designate  them  almost  always  under  the  name  of  mem- 
branes. Their  study  is  a new  object  of  research.  Pinel 
has  been  among  the  first,  who  has  perceived  the  necessity 
of  considering  them  in  a general  manner  as  it  respects 
diseases.  I believe  that  I am  the  first  who  has  regarded 
them  generally  in  an  anatomical  and  physiological  view. 
Few  systems  deserve  more  attention  ; upon  it  take  place 
all  the  great  phenomena  of  digestion,  respiration,  secretion, 
excretion,  &c.  ; it  is  the  seat  of  many  diseases.  It  should 
alone,  in  a nosography  in  which  diseases  are  distributed 
by  systems,  occupy  a place  equal  to  that  of  many. 


ARTICLE  FIRST. 

OF  THE  DIVISIONS  AND  FORMS  OF  THE  MHCOITS  SYSTEM. 

The  mucous  membranes  occupy  the  interior  of  the 
cavities  which  communicate  with  the  skin  by  the  different 
openings  this  covering  has  on  the  surface  of  the  body. 
VOL,  III.  9 


66 


MUCOUS  SYSTEM. 


Their  number  at  first  view  is  very  considerable  ; for  the 
organs  in  which  they  are  reflected  are  very  numerous. 
The  mouth,  the  stomach,  the  intestines,  the  oesophagus, 
the  bladder,  the  urethra,  the  womb,  the  ureters,  all  the 
excretories,  &c.  &c.  derive  from  these  membranes  a part 
of  their  structure.  Yet  if  we  consider  that  wherever  they 
are  continuous,  wherever  we  see  them  originate,  by  ex- 
tending from  each  other,  as  they  originated  in  the  first 
instance  from  the  skin,  we  shall  perceive  that  this  number 
must  be  wonderfully  limited.  In  fact  by  thus  describing 
them,  not  separately  in  each  part,  but  at  the  same  time  in 
all  those  upon  which  they  are  continued,  we  see  that  the)^ 
are  reduced  to  two  general  surfaces,  of  which  all  the 
others  are  portions,  and  which,  on  account  of  the  differ- 
ent parts  to  which  they  are  distributed,  can  be  called,  the 
one  gastro-pulmonary,  the  other  genito-urinary.  The 
first  is  found  in  the  head,  the  neck  and  the  abdomen. 
This  last  cavity  and  more  especially  the  pelvis,  contain  the 
second. 

There  is  also  a small  insulated  mucous  surface  ; it  is  that 
which  enters  by  the  openings  of  the  nipples  and  lines  the 
lactiferous  tubes.  But  it  is  so  small  that  it  deserves  but 
little  attention ; besides,  what  will  be  said  of  the  two 
others  will  be  equally  applicable  to  it.  It  is  then  useless 
to  examine  it  in  a general  manner. 

I.  Of  the  tioo  General  Mucous  Membranes,  the  Gas- 
tro-Pulmonary  and  the  Genito-JJrinary. 

The  gastro-pulmonary  surface  penetrates  into  the  in- 
terior by  the  mouth,  the  nose  and  the  anterior  face  of  the 
eye.  1st.  It  lines  the  first  and  second  of  these  cavities, 
extends  from  the  first  to  the  excretory  ducts  of  the  parotid 
and  sub-maxillary  glands,  from  the  other  into  all  the 
sinuses,  forms  the  conjunctiva,  dips  down  into  the  puncta 
lachrymalia,  the  nasal  duct,  the  sac  of  the  same  name, 
and  is  continued  into  the  nose  ; 2d,  it  descends  into  the 


MUCOUS  SYSTEM. 


67 


pharynx,  furnishes  an  elongation  to  the  Eustachian  tube? 
then  penetrates  the  internal  ear  and  lines  it,  as  we  shall 
see  ; 3d,  it  dips  down  into  the  trachea  and  is  spread  upon 
all  the  air-tubes ; 4th,  it  penetrates  into  the  oesophagus 
and  the  stomach  ; 5th,  it  extends  to  the  duodenum  where 
it  furnishes  two  elongations,  one  destined  to  the  ductus 
choledochus,  to  the  numerous  branches  of  the  hepatic  and 
cystic  ducts  and  the  gall-bladder,  the  other  to  the  pancre- 
atic duct  and  its  different  branches  ; 6th,  it  is  continued 
into  the  small  and  large  intestines  and  finally  terminates 
at  the  anus  where  we  see  it  identified  with  the  skin. 

The  second  genei'al  mucous  membrane,  which  we  have 
called  the  genito-urinaiy,  enters  in  man  by  the  urethra, 
and  thence  is  spread  on  the  one  hand  upon  the  bladder, 
the  ureters,  the  pelvis  of  the  kidnies,  the  infundibula,  the 
papillae  and  the  capillary  tubes  which  open  on  their  sum- 
mit ; on  the  other  hand  it  goes  into  the  excretory  tubes  of 
tbe  prostate,  into  the  seminal  ducts,  the  vesiculae  semi- 
nales,  the  vasa  deferentia  and  the  branches  with  number- 
less windings  that  produce  them. 

In  woman,  this  membrane  is  introduced  by  the  os  ex- 
ternum and  penetrating  on  the  one  hand  by  the  urethra, 
goes  as  in  man  upon  the  urinary  organs  ; on  the  other  hand, 
we  see  it  enter  the  vagina,  lining  it,  the  uterus  and  the 
fallopian  tubes,  and  afterwards  becoming  continuous  with 
the  peritoneum  b)’  the  opening  of  these  tubes.  It  is  the 
only  example  in  the  economy,  of  a communication  estab- 
lished between  the  mucous  and  serous  surfaces. 

This  manner  of  describing  the  course  of  the  mucous 
surfaces,  by  saying  that  they  are  elongated,  dip  down, 
penetrate,  &c.  from  one  cavity  to  another,  is  no  doubt 
not  conformable  to  the  progress  of  nature,  which  creates 
in  each  organ  the  membranes  belonging  to  this  organ,  and 
does  not  thus  extend  them  by  degrees ; but  our  manner 
of  understanding  it  is  better  adapted  to  this  language, 
the  meaning  of  which  the  least  reflection  will  show. 


68 


MUCOUS  SYSTEM. 


In  thus  referring  to  two  general  membranes  all  the 
mucous  surfaces,  I am  not  only  supported  by  anatomical 
inspection,  but  pathological  observation  has  also  furnished 
me  with  points  of  demarcation  between  the  two,  and 
points  of  contact  between  the  different  portions  of  mem- 
branes of  which  each  is  the  assemblage.  In  the  different 
descriptions  of  catarrhal  epidemics  given  by  authors,  we 
frequently  see  one  of  these  membianes  affected  in  all 
parts,  the  other  remaining  sound  ; it  is  especially  not  rare 
to  observe  a general  affection  of  the  first,  of  that  which 
extends  from  the  mouth,  the  nose, -the  surface  of  the  eye, 
into  the  alimentary  canal  and  the  bronchial  vessels.  The 
last  epidemic  observed  at  Paris,  with  which  Pinal  himself 
was  affected,  was  of  this  character  ; that  of  1761,  described 
by  Razou,  had  it  also;  that  of  1752,  described  in  the  me- 
moi-rs  of  the  Society  of  Edinburgh  was  remarkable  for  a 
similar  phenomenon  ; now,  we  do  not  see  at  that  time  a 
corresponding  affection  in  the  mucous  membrane  that  is 
spread  upon  the  urinar)'^  organs  and  upon  those  of  genera- 
tion. There  is  then  here,  1st,  an  analogy  between  the 
portions  of  the  first,  by  the  uniformity  of  affection  ; 2d, 
a demarcation  belvv^een  the  two  by  the  health  of  the  one 
and  the  disease  of  the  other. 

We  see  also  that  the  irritation  of  any  one  point  of  one 
of  these  membranes,  frequently  produces  a pain  in  another 
point  of  the  same  membrane,  which  is  not  irritated. 
Thus  a calculus  in  the  bladder  occasions  a pain  at  the  end 
of  the  glans  penis,  the  presence  of  worms  in  the  intes- 
tines causes  an  itching  of  the  nose,  &c.  &c.  Now,  in 
these  phenomena  purely  sympathetic,  it  is  very  rare  that 
the  partial  irritation  of  one  of  these  two  membranes 
affects  with  pain  one  of  the  parts  of  the  other  ; there  are 
however  examples  of  it;  such  is  the  singular  relation 
that  exists,  in  mucous  hemorrhages,  between  the  mem- 
brane of  the  womb  and  that  of  the  bronchia.  If  the 
blood  ceases  accidentally  to  flow  from  one  during  meiistru- 


MUCOUS  SYSTEM. 


69 


ation,  the  other  frequently  exhales  it  and  thus  as  it  were 
supplies  its  functions. 

We  ought  then,  from  inspection  and  observation,  to 
consider  the  mucous  surface,  in  general,  as  formed  by  two 
great  membranes  successively  spread  upon  many  organs, 
having  between  them  no  communication  except  by  the 
skin,  which  serves  them  as  an  intermediate  organ,  and 
which,  continuing  with  both,  contributes  thus  with  them 
to  form  a general  membrane  everywhere,  continuous, 
covering  the  animal  externally,  and  extending  within 
upon  most  of  its  essential  parts.  We  can  conceive  that 
there  should  exist  important  relations  between  the  inter- 
nal and  external  portion  of  this  single  membrane  ; and 
that  they  do  will  be  proved  by  further  researches, 

II.  Jidhering  Surface  of  the  Mucous  Membranes. 

Every  mucous  membrane  exhibits  two  surfaces,  one 
adhering  to  the  neighbouring  organs,  the  other  free, 
covered  with  villi,  always  moistened  with  a mucous  fluid. 
Each  deserves  particular  attention. 

The  adhering  surface  corresponds  almost  everywhere 
with  the  muscles,  either  of  animal  or  organic  life.  The 
mouth,  the  pharynx,  the  whole  alimentary  canal,  the 
bladder,  the  vagina,  the  womb,  a portion  of  the  urethra, 
&c.  exhibit  a muscular  layer  embracing  on  the  outside 
their  mucous  tunic  which  is  within.  This  arrangement 
coincides  perfectly,  in  animals  with  a fleshy  membrane, 
with  that  of  the  skin,  which  moreover  approximates  very 
near,  as  we  shall  see,  the  structure  of  the  mucous  mem- 
branes, and  which,  as  we  have  seen,  is  everywhere  con- 
tinuous with  them.  This  arrangement  of  the  mucous 
membranes  occasions  them  to  be  agitated  by  constant 
motions  which  favour  wonderfully  the  secretion  that 
takes  place  in  them,  the  excretion  which  succeeds  it,  and 
the  various  other  functions  of  which  they  are  the  seat.  The 


70 


MUCOUS  SYSTEM. 


insertion  of  this  muscular  layer  exterior  to  the  mucous 
system,  is  made,  as  we  have  seen,  by  this  dense  and  com- 
pact texture  which  I have  called  the  sub-mucous.  It  is 
from  this  texture,  more  compact  than  the  rest  of  the  cellu- 
lar system,  that  the  mucous  surface  derives  its  force.  It 
is  from  it  that  the  organ  which  it  lines  receives  its  form  ; 
it  is  this  which  supports  and  preserves  this  form  ; the 
following  experiment  proves  it.  Take  a portion  of  the 
intestine  ; remove  from  any  part  of  it  this  layer,  as  well 
as  the  serous  and  the  muscular ; then  inflate  it,  after  hav- 
ing tied  it  below  ; the  air  produces  in  this  place  a hernia 
of  the  mucous  coat.  Try  afterwards  another  portion  of 
intestine  ; deprive  this,  for  a small  space,  of  its  mucous 
membrane  and  of  this  also  ; inflation  will  produce  upon 
the  serous  and  muscular  tunics  the  same  phenomenon 
that  it  did  in  the  preceding  on  the  mucous  ; then  it  is  to 
this  sub-mucous  cellular  layer  that  it  owes  the  resistance 
with  which  it  opposes  substances  that  it  contains.  The 
same  may  be  said  of  the  stomach,  tlie  bladder,  the  oeso- 
phagus, &c. 

III.  Free  Surface  of  the  Mucous  Membranes. 

The  free  surface  of  the  mucous  membranes,  that  which 
is  continually  moistened  by  the  fluid  from  which  they 
borrow  their  name,  exhibits  three  species  of  wrinkles  or 
folds. 

1st.  One  inherent  in  the  structure  of  all  the  laminae  of 
these  membranes,  is  constantly  met  with,  whatever  may 
be  their  state  of  dilatation  or  contraction  ; such  are  those 
of  the  pylorus  and  the  valve  of  Bauhin.  These  folds  are 
formed  not  only  by  the  mucous  membrane,  but  also  by 
the  intermediate  tunic  of  which  we  have  spoken,  which 
here  has  a remarkable  density  and  thickness,  and  gives 
them  solidity.  The  fleshy  tunic  enters  even  into  their 
composition,  and  we  see  on  the  exterior,  upon  the  serous 
surface,  a depression  that  indicates  their  presence. 


filUCOUS  SYSTEM. 


71 


2d.  Other  folds,  only  formed  by  the  mucous  surface,  exist 
also  always  in  a state  of  vacuity  or  fulness,  less  evident 
however  than  this ; they  are  owing  to  the  circumstance 
that  the  mucous  surface  is  much  more  extensive  than  those 
ilpon  which  it  is  applied,  so  that  it  is  folded  that  it  may 
not  run  a longer  course  ; such  are  the  valvulse  conniventes 
of  the  small  intestines,  the  structure  of  which  we  see  very 
well  by  cutting  longitudinally  one  of  these  intestines. 
The  edge  of  the  section  exhibits  the  fleshy  layer  and*  the 
serous  surface  in  a straight  direction,  whilst  the  mucous 
layer  describes  a line  resembling  a loose  thread. 

3d.  The  last  species  of  folds  is  as  it  were  accidental, 
and  is  only  observed  during  the  contraction  of  the  organ 
which  is  lined  by  the  mucous  surface  that  is  the  seat  of 
it ; such  are  those  of  the  interior  of  the  stomach,  the 
great  intestines,  &c.  In  the  greatest  number  of  subjects 
brought  to  the  dissecting  rooms,  these  folds  of  which  so 
much  has  been  said  as  it  respects  the  stomach,  cannot  be 
perceived  in  it,  because  the  subject  has  died  after  a dis- 
ease that  has  so  altered  the  vital  forces,  as  to  prevent  all 
action  of  this  viscus  ; so  that  though  it  is  frequently  found 
empty,  its  fibres  are  not  contracted.  In  experiments 
upon  living  animals,  on  the  contrary,  these  folds  become 
very  evident,  and  may  be  demonstrated  in  this  way  ; 
make  a dog  eat  or  drink  copiously,  open  him  an  instant 
after  and  cut  the  stomach  in  the  length  of  its  great  curva- 
ture ; no  fold  is  then  apparent ; but  soon  the  viscus  con- 
tracts, its  edges  are  turned  over  and  the  aliments  escape  ; 
the  whole  mucous  surface  is  covered  with  an  infinite 
number  of  very  prominent  ridges,  which  have  as  it  were 
the  form  of  cerebral  circumvolutions.  We  obtain  the 
same  result  by  taking  out  the  stomach  of  an  animal 
recently  killed,  distending  it  with  air  and  opening  it 
afterwards,  or  by  cutting  it  immediately  in  its  state  of 
vacuity  and  drawing  it  in  opposite  directions  by  its  edges; 
it  stretches,  its  ridges  disappear,  and  if  we  cease  to  dis- 


72 


MUCOUS  SYSTEM, 


tend  it,  they  form  again  immediately  in  an  evident  man- 
ner. I would  observe  on  the  subject  of  the  inflation 
of  the  stomach,  that  by  distending  it  with  oxygen,  we 
do  not  produce  by  the  contact  of  this  gas,  greater  ridges 
and  consequently  a stronger  contraction,  than  by  using 
for  the  same  purpose  carbonic  acid  gas.  This  experiment 
furnishes  a result  very  similar  to  what  I have  observed  in 
rendering  animals  emphysematous  by  different  aeriform 
fluids.  It  follows  from  all  that  we  have  said  upon  the 
folds  of  the  mucous  membranes,  that  in  the  ordinary  con- 
traction of  the  hollow  organs  which  these  membranes  line 
they  undergo  but  a very  slight  diminution  of  surface,  that 
they  contract  scarcely  at  all,  but  fold  within,  so  that  by 
dissecting  them  on  an  organ  in  contraction  we  should 
have  a surface  almost  equal  in  extent  to  that  which  they 
exhibit  during  its  dilatation.  This  assertion,  which  is 
true  as  it  respects  the  stomach,  the  oesophagus  and  the 
great  intestines,  is  not  perhaps  as  entirely  so  with  regard 
to  the  bladder,  the  contraction  of  which  makes  the  ridges 
within  less  evident ; but  they  are  not  sufficient  to  destroy 
the  general  law.  It  is  also  nearly  the  same  with  the  gall- 
bladder ; yet  here  we  find  another  cause.  The  gall-bladder, 
alternately  observed  in  hunger  and  during  digestion,  con- 
tains double  the  bile  in  the  first  case  that  it  does  in  the 
second,  as  I have  had  occasion  to  see  very  often  indeed, 
in  experiments  made  for  this  object  or  with  other  views. 
Now,  when  the  bladder  is  in  part  empty,  it  does  not  con- 
tract upon  the  bile  that  remains,  with  the  force  of  the 
stomach  when  it  contains  but  few  aliments,  or  with  the 
power  of  the  bladder  when  it  contains  but  little  urine.  It 
is  then  flaccid  ; so  that  its  being  distended  or  not  has  but 
a slight  influence  upon  the  folds  of  its  mucous  membrane. 

Besides,  in  saying  that  the  mucous  membranes  always 
exhibit,  with  some  slight  difference,  the  same  surface  in 
the  extension  and  contraction  of  their  respective  organs, 
I intend  to  speak  only  of  the  ordinary  state  of  the  func- 


MUCOUS  SYSTEM. 


73 


lions,  and  not  of  those  enormous  dilatations  of  which  we 
often  see  the  stomach,  the  bladder,  and  more  rarely  the 
intestines  become  the  seat.  Then  there  is  no  doubt,  a 
real  extension  and  contraction,  which  coincide  in  the 
membrane  with  those  of  the  organ. 

A remarkable  observation  which  the  free  surface  of  the 
mucous  membranes  exhibits,  and  which  I have  already 
pointed  out,  is,  that  this  surface  is  everywhere  in  contact 
with  bodies  heterogenous  to  that  of  the  animal,  whether 
these  bodies  introduced  from  without  to  nourish  it  have 
not  yet  been  assimilated  to  its  substance,  as  we  see  in  the 
alimentary  canal  and  in  the  wind-pipe  ; or  whether  they 
come  from  within,  as  we  observe  in  all  the  excretory 
ducts  of  the  glands,  which  all  open  into  cavities  lined  by 
the  mucous  membranes,  and  transmit  without  particles 
which,  after  having  contributed  for  some  time  to  the  com- 
position of  the  solids,  become  'heterogeneous  to  them, 
and  are  separated  from  them  by  the  constant  motion  of 
decomposition  which  takes  place  in  living  bodies.  Hence 
we  ought  to  regard  the  mucous  membranes  as  limits,  and 
barriers,  which,  placed  between  our  organs  and  the  bodies 
that  are  foreign  to  them,  defend  them  from  the  mis- 
chievous impression  of  these  bodies,  and  serve  conse- 
quently within,  the  same  functions  which  the  skin  per- 
forms without,  with  respect  to  the  bodies  which  surround 
that  of  the  animal,  and  which  tend  incessantly  to  act 
upon  it. 

The  organization  of  the  mucous  system  and  its  vital 
properties  are  accommodated  to  this  habitual  contact  of 
substances  heterogeneous  to  the  living  economy.  That 
which  is  a foreign  body  to  the  other  systems,  the  cellular, 
the  muscular,  &c.  is  not  so  to  this.  Solid  substances,  the 
metals,  stones,  wood,  &c.  which  introduced  into  our  parts 
excite  in  them  inevitably  suppuration  and  an  antecedent 
inflammation  by  their  simple  contact,  pass  with  impunity 
over  this,  provided  that  their  angles  and  asperities  do  not 
VOL.  III.  10 


74 


MUCOUS  SYSTEM. 


tear  it ; they  only  augment  a little  the  secretion,  as  I 
shall  say.  We  can  swallow  a ball  of  lead,  of  wood,  &c.  and 
pass  it  by  the  anus  without  inconvenience.  All  the  irri- 
tating fluids  without  being  caustic,  that  we  inject  into  the 
great  intestines  in  enemas,  or  that  we  swallow,  would 
produce  abscesses,  &c.  if  they  were  forced  into  the  cellu- 
lar system,  &c.  Surgeons  employ  the  term  foreign  bodies 
in  too  general  a manner  ; that  which  is  so  for  one  system, 
is  not  for  another.  Foreign  is,  in  this  respect,  a term  of 
comparison  which  we  should  employ  only  after  a know- 
ledge of  the  peculiar  sensibility  of  each  system,  and  not 
after  that  of  this  property  described  in  a vague  manner. 

The  mucous  system,  not  only  bears  without  danger  the 
presence  of  all  bodies  that  are  introduced  into  the  eco- 
nomy, but  also  when  it  goes  out,  it  can  be  exposed  with 
impunity  to  the  contact  of  external  stimuli.  Observe 
what  takes  place  in  prolapsus  of  the  womb  in  which  the 
whole  membrane  of  the  vagina  sometimes  becomes  exter- 
nal, in  those  inversions  of  the  intestinal  tubes  that  take 
place  through  preternatural  ani,  in  prolapsus  of  the  rec- 
tum, &c. ; then  the  mucous  surfaces  serve  really  as  inte- 
guments ; now  in  these  cases  the  surrounding  bodies  pro- 
duce hardly  any  more  pain  on  them  than  upon  the  skin. 
On  the  contrary,  the  instant  a serous  surface  is  laid  bare, 
as  for  example  in  tbe  operation  of  hernia,  in  which 
the  intestine  is  suffered  to  come  out,  on  account  of  an 
opening  unfortunately  made  by  the  point  of  a bistoury, 
this  surface  inevitably  inflames.  All  the  cellular,  mus- 
cular, nervous,  glandular  systems,  &c.  laid  bare,  exhibit 
the  same  phenomenon.  There  is  no  danger  in  opening 
the  bladder  as  it  respects  the  contact  of  the  air,  whilst 
there  is  much  in  permitting  this  fluid  to  penetrate  into  an 
articular  cavity,  a tendinous  groove,  a serous  sac,  &c. 
We  know  how  much  in  the  high  operation  for  the  stone, 
we  fear  to  wound  the  peritoneum,  how  uncertain  are  the 
results  of  empyema  on  account  of  the  contact  of  the  air 


MUCOUS  SYSTEM. 


75 


upon  the  pleura,  &c.  The  dangers  of  the  action  of  this 
fluid  upon  these  surfaces  have  been  perhaps  exaggerated, 
but  they  are  notwithstanding  real. 

If  a fistula  extends  from  the  exterior  of  the  abdomen 
into  the  intestines,  its  whole  course  is  lined  with  callous 
bodies  ; these  defend  the  cellular  texture  and  the  muscles 
through  which  the  fistula  passes.  On  the  contrary, 
nothing  similar  appears  upon  the  intestinal  mucous  sur- 
face, because  its  organization  alone  is  sufficient  to  protect 
it.  The  urinary,  salivary  and  lacrjunal  fluids  never 
escape  externally  by  artificial  ducts  formed  in  the  neigh- 
bouring organs,  without  there  are  similar  callous  bodies 
in  the  course  of  these  ducts  ; on  the  contrary,  they  pass 
with  impunity  over  the  mucous  surfaces.  Make  in  a limb  a 
long  and  straight  opening  with  a pointed  instrument,  and 
fix  in  it  for  a time  a sound  ; a callous  canal  W'ill  be  pro- 
duced by  it.  Let  a sound  on  the  contrary  remain  in  the 
urethra,  no  alteration  of  texture  will  result  from  it. 

Let  us  conclude  from  these  different  considerationsj 
that  the  mucous  system  with  the  cutaneous  alone,  is 
organized  so  as  to  support  the  contact  of  all  external 
bodies,  and  not  to  be  affected  by  their  presence,  or  at 
least  experience  only  an  increase  of  secretion,  which  is  in 
no  ways  dangerous.  Thus  these  two  systems  form  two 
boundaries,  the  one  internal  and  the  other  external,  be- 
tween which  are  placed  the  organs  foreign,  by  their 
mode  of  sensibility  and  by  that  of  their  structure,  to 
the  external  bodies.  To  these  boundaries  the  excitement 
of  these  bodies  is  limited  ; their  influence  does  not  go 
beyond.  So  long  as  they  do  not  pass  these  boundaries, 
the  other  organs  do  not  feel  them.  We  might  say  that 
the  acute  sensibility  which  each  of  them  enjoys,  is  a kind 
of  sentinel  that  nature  has  placed  on  the  confines  of  the 
organic  domain  of  the  mind,  to  inform  it  of  whatever  can 
injure  it. 


76 


MUCOUS  SYSTEM, 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  MUCOUS  SYSTEM. 


I.  Texture  Peculiar  to  this  Organization. 

The  mucous  system  presents  two  things  to  be  consid- 
ered in  its  peculiar  texture,  viz.  1st,  a layer  more  or  less 
thick  which  constitutes  principally  this  texture,  and  which 
by  analogy  with  the  cutaneous  corion,  may  be  called 
the  mucous  corion  ; 2d,  many  small  elongations  which 
surmount  it,  and  which  are  called  villi  or  papillas.  As  to 
the  epidermis  which  covers  it,  I shall  treat  of  it  with  the 
cutaneous  epidermis.  This  texture  has  nothing  similar 
to  the  substance  that  colours  the  skin,  and  which  is  be- 
tween the  papillae  and  epidermis.  We  know  in  fact  that 
negroes,  as  well  as  whites,  have  this  texture  of  a bright 
red,  which  it  derives  from  its  vessels. 

Mucous  Corion. 

This  portion  of  the  mucous  texture,  which  is  the  most 
important,  and  which  constitutes  the  thickness,  form,  and 
even  the  nature  of  it,  has  a soft  and  spongy  appearance. 
We  might  say  at  first  view  that  it  was  a consistent  pulp, 
with  which  the  .extremely  dense  cellular  texture  that  is 
subjacent  to  it  had  been  covered.  This  softness  is  a 
character  which  distinguishes  it  from  the  cutaneous  corion, 
which  moreover  has  by  its  intimate  nature  but  little  re- 
semblance to  it. 

The  mucous  corion  is  very  various  as  to  thickness ; it 
differs  in  this  respect  in  each  organ.  That  of  the  gums 
and  the  palate  is  the  thickest  of  all.  Then  come  those  of 


MUCOUS  SYSTEM. 


77 


the  nasal  fossse  and  the  stomach,  then  those  of  the  small 
intestines  and  the  gall-bladder,  then  those  of  the  large 
intestines,  of  the  urinary  bladder,  the  urethra  and  the 
other  excretories,  until  it  begins  at  length  to  become  so 
fine  as  to  appear  transparent  like  a serous  surface  when  it 
is  removed  with  care.  Finally,  the  finest  and  most  deli- 
cate is  that  of  the  sinuses  of  the  face  and  the  interior  of 
the  ear;  the  arachnoides  is  often  coarser. 

I have  called  the  texture  within  the  ear  mucous,  though 
all  anatomists  call  the  membrane  of  the  cavities  of  this 
organ . periosteum.  In  fact,  1st,  we  see  it  evidently  con- 
tinued with  the  pituitary  membrane,  by  means  of  the 
elongation  of  the  Eustachian  tube.  2d.  We  find  it  con- 
stantly moistened  by  a mucous  fluid  which  this  canal 
serves  to  convey  out,  a character  foreign  to  the  perios- 
teum, which,  like  the  fibrous  membranes,  always  adheres 
by  both  its  surfaces.  3d.  No  fibre  can  b.e  distinguished  in 
it.  4th.  Its  fungous  appearance,  though  white  and  soft, 
and  the  ease  with  which  it  is  torn,  are  evident  attributes 
of  the  mucous  membranes.  Every  thing  proves  that  the 
membrane  of  the  tympanum,  that  of  the  meatus,  &c.  be- 
long to  the  system  of  which  we  ai’e  treating.  Thus  in 
catarrhs  of  the  pituitary  membrane,  and  of  that  of  the 
fauces,  we  most  often  find  that  the  ear  is  affected  ; thus 
the  ear  is,  like  the  mucous  surfaces,  the  seat  of  hemorr- 
hage, thus  polypi  arise  in  it,  as  in  the  nose  and  on  the 
surface  of  the  womb.  We  consider  as  a sign  of  deposi- 
tion of  pus  in  the  ear,  every  purulent  discharge  coming 
from  that  cavity.  But  how  can  we  conceive  of  a puru- 
lent collection  in  a part  in  which  there  is  hardly  any 
cellular  texture,  in  a part  wholly  osseous  ? Besides  the 
fibrous  system,  to  which  the  periosteum  of  the  tympanum 
belongs,  hardly  ever  suppurates,  as  we  know.  Every 
thing  then  induces  us  to  believe  that  these  discharges  are 
only  the  effect  of  a catarrh  of  the  ear,  a catarrh  which  is 
sometimes  acute  and  sometimes  chronic.  I have  more- 


78 


MUCOUS  SYSTEM. 


over  a recent  and  decisive  fact  upon  this  point ; the  body 
of  a man  subject  to  these  discharges  during  life  exhibited 
a remarkable  thickness  and  redness  of  the  membrane  of 
the  tympanum,  but  without  the  least  trace  of  erosion. 
The  ear  suppurates  like  the  urethra,  the  vagina,  &c.  it  is 
not  a new  fluid  which  is  formed  by  suppuration  ; it  is 
that  which  naturally  comes  from  the  meatus  which  in- 
creases in  quantity  and  comes  through  a preternatural 
opening  of  the  membrane  of  the  tympanum. 

Diseases  make  the  thickness  of  all  the  mucous  surfaces 
vary  remarkably.  I have  seen  them  many  lines  thick  in 
the  maxillary  sinus,  and  nearly  half  an  inch  in  the  blad- 
der. In  great  extensions  of  the  mucous  sacs,  this  thick- 
ness diminishes  very  much  ; it  increases  in  their  contrac- 
tions. The  stomach  especially  exhibits  this  phenomenon 
in  these  two  opposite  states. 

The  softness  of  the  mucous  corion  is  also  very  variable ; 
in  the  nasal  fossae,  in  the  stomach  and  the  intestines,  it  is 
really  a kind  of  organized  velvet.  The  name  of  villous 
membrane  is  perfectly  suited  to  it.  On  the  contrary,  at  the 
origins  of  the  mucous  system,  as  in  the  mouth,  upon  the 
glans  penis,  at  the  entrance  of  the  nose,  it  is  a more  dense 
and  compact  texture,  approximating  nearer  in  its  nature 
to  the  cutaneous  corion.  I am  persuaded  that  like  this  it 
might  be  tanned  and  be  useful  in  the  arts  if  it  were  in 
larger  pieces,  whilst  I doubt  if  the  action  of  tanning 
could  produce  an  analogous  phenomenon  upon  the  mu- 
cous texture  of  the  deep-seated  organs.  The  softness  of 
this  would  render  it  incapable  of  serving  for  external  in- 
teguments. The  least  cause  would  be  in  fact  sufficient  to 
break  and  tear  it.  Its  structure  being  different  from 
that  of  the  cutaneous  corion  is  the  reason  that  the  vario- 
lus  pustules  never  appear  on  it,  whilst  we  often  see  them 
on  the  mucous  surfaces  near  the  openings  of  the  skin, 
especially  upon  the  tongue,  the  palate  and  the  internal 
surface  of  the  cheeks. 


MUCOUS  SYSTEM. 


79 


Exposed  to  the  action  of  dry  air,  so  that  it  may  come 
everywhere  in  contact  with  it,  it  becomes  dry  and  very 
thin,  but  preserves  some  resistance.  In  bladders  inflated 
and  dried,  in  the  stomach,  the  intestines,  &c.  thus  pre- 
pared, it  is  this  texture  which  supports  these  organs,  and 
which  prevents  them  from  becoming  flat,  though  we  per- 
mit the  air  to  escape ; it  ofiers  even  a resistance,  from 
which  arises  a kind  of  crepitation  when  we  wish  to  bend 
them  in  various  directions.  To  be  convinced  of  this,  it 
is  only  necessary  to  dry  the  mucous  surface  separate  from 
the  serous  and  muscular  that  correspond  with  it ; these 
when  dried  remain  pliable  like  the  cellular  texture,  whilst 
the  first  has  a kind  of  rigidity. 

In  the  organs  in  which  the  redness  of  the  mucous  tex- 
ture  is  slight,  as  in  the  bladder,  the  rectum,  &c.  it  be- 
comes transparent  by  drying.  Where  it  is  very  red  as 
in  the  stomach,  it  takes  a deep  tinge,  which  becomes  even 
almost  black  if  there  had  been  an  antecedent  inflamma- 
tion in  it  by  which  much  blood  had  been  accumulated  ; 
hence  it  appears  that  this  fluid  is  the  cause  of  the  colour. 

Thus  dried  the  mucous  surfaces  are  smooth  ; they  lose 
their  viscidity  at  least  in  appearance  ; their  folds  are 
efiaced  by  adhering  to  the  surface  from  which  they  arise ; 
thus  the  valvulse  conniventes  are  marked  in  a dried  intes- 
tine, only  by  a red  line,  without  any  apparent  promi- 
nence. But  if  we  macerate  the  intestines  in  this  state, 
the  folds  form  again  and  become  visible. 

Exposed  to  a moist  air,  or  left  with  other  flesh  that  will 
not  allow  it  to  become  dry,  the  mucous  corion  putrefies 
with  great  ease ; the  odour  that  it  then  sends  out  is  very 
fetid.  I think  the  reason  why  the  abdomen  of  dead  bodies 
becomes  putrid  so  soon  is  in  part  because  it  contains  sub- 
stances already  in  putrefaction,  and  also  because  the  sur- 
faces, in  contact  with  these  substances,  and  which  by  their 
vitality  resisted  before  their  action,  then  readily  yield  to 
them.  If  these  substances  were  contiguous  to  aponeu- 


60 


MUCOUS  SYSTEM. 


roses,  putrefaction  would  be  much  less  rapid.  The 
mucous  system  when  putrid  takes  a greyish  colour  ; and 
as  the  dense,  subjacent  cellular  texture  putrefies  much 
less  easily,  we  can  then  remove  from  it  by  the  least  pres- 
sure, the  mucous  corion,  reduced  to  a putrid  pulp,  in 
which  every  trace  of  organization  has  disappeared,  and 
which  forms  a real  pap. 

During  life,  gangrene  of  the  mucous  texture  takes  place 
in  general  less  frequently  than  that  of  the  cutaneous. 
The  consequences  of  catarrh,  compared  with  those  of 
erysipelas  may  convince  us  of  this ; there  are  however 
cases  in  which  death  appears  in  this  texture,  whilst  the 
surrounding  ones  continue  to  live,  as  in  gangrenous 
angina. 

Exposed  to  maceration,  the  mucous  texture  yields  to  it 
promptly.  I think  that  next  to  the  brain  it  is  altered 
quickest  by  the  action  of  water.  It  is  then  reduced  to 
a reddish  pulp  very  different  from  that  from  putrefaction 
in  the  open  air.  When  we  put  the  whole  stomach  to 
macerate,  this  pulp  is  detached,  when  the  sub-mucous 
texture  and  the  serous  membrane  have  as  yet  undergone 
but  little  alteration. 

Ebullition  at  first  extracts  from  the  mucous  texture  a 
greenish  scum,  very  different  from  that  which  the  mus- 
cular and  cellular  textui'es  give  when  boiled.  This  scum 
which  mixed  with  the  whole  fluid  in  the  beginning  of 
the  boiling,  disturbs  it  and  renders  it  green  at  first,  after- 
wards rises  upon  the  surface  where  it  has  small  bubbles 
of  air  mixed  with  its  substance ; it  often  even  falls  to  the 
bottom  of  the  vessel  by  its  weight.  Sulphuric  acid  changes 
the  colour  of  it  to  a dull  brown. 

A short  time  before  the  water  begins  to  boil,  the  mu- 
cous texture  crisps  and  acquires  the  horny  hardness  like 
the  others,  but  in  a less  degree  however  ; hence  why  it 
is  then  wrinkled  almost  always  in  different  directions.  In 
fact,  the  sub-mucous  texture  upon  which  it  is  applied, 


MUCOUS  SYSTEM. 


81 


contracting  at  that  time  much  more  than  it,  it  must  fold 
on  account  of  its  length  ; thus  during  life,  when  the 
fleshy  coat  of  the  stomach  contracts,  its  mucous  surface 
not  contracting  in  proportion,  produces  the  numerous 
folds  of  which  we  have  spoken.  The  action  of  a concen- 
trated acid  crisping  the  sub-mucous  texture  more  than 
the  mucous  itself,  produces  an  analogous  phenomenon. 
After  having  been  a long  time  dried,  the  mucous  texture, 
like  however  almost  all  those  of  the  animal  economy,  does 
not  lose  the  faculty  of  acquiring  the  horny  hardness  when 
it  is  plunged  into  boiling  water ; it  exhibits  this  pheno- 
menon, whether  we  expose  it  to  it  dry,  or  whether  w'e  do 
it  after  having  first  softened  it  in  cold  water.  It  is  a 
means  by  which  all  the  valvules  conniventes  may  be  made 
suddenly  to  reappear,  which  had  disappeared  by  drying, 
and  which  form  again  the  instant  the  intestine  contracts. 
This  experiment  is  very  curious  to  witness. 

When  the  ebullition  has  been  a long  time  continued,  the 
mucous  texture  turns  gradually  to  a very  deep  grey,  from 
the  white  which  it  had  first  become.  It  is  not  softer  than 
in  the  natural  state,  but  it  breaks  much  quicker ; the  fol- 
lowing experiment  is  a proof  of  it.  If  we  draw  the  mu- 
cous corion,  boiled  for  some  time  with  the  subjacent  cel- 
lular texture,  this  last  resists  the  most ; so  that  it  remains 
entire,  whilst  the  mucous  corion  is  broken  in  many  places. 
This  never  assumes  the  gelatinous  appearance  of  the  cuta- 
neous corion  or  the  fibrous  and  cartilaginous  organs  when 
boiled  and  of  the  others  which  yield  much  gelatine. 
However  by  mixing  a solution  of  tannin  with  the  water 
in  whjch  this  system  taken  from  an  adult  has  been  boiled, 
I have^seen  an  evident  precipitate. 

The  action  of  the  acids  reduces  to  a pulp  the  mucous 
texture  much  sooner  than  most  of  the  others.  During 
life,  all  the  caustics  act  much  more  rapidly  upon  it  than 
upon  the  cutaneous,  of  W'hich  the  thick  epidermis  is  an 
intermediate  organ  which  checks  their  tendency  of  com- 

VOL.  III.  1 1 


82 


MUCOUS  SYSTEM, 


bining  with  its  corion.  Thus  the  instant  the  nitric  acid, 
a substance  which  common  people  almost  always  choose 
for  their*  poison,  as  the  practice  at  the  Hotel  Dieu  proves, 
thus  the  instant  I say,  that  the  nitric  acid  is  in  contact 
with  the  alimentary  canal,  it  disorganizes  it,  it  forms 
there  a whitish  eschar,  which,  when  death  does  not  take 
place  immediately,  as  most  often  happens,  is  slowly  re- 
moved and  detached  in  the  form  of  a membrane.  We 
know  that  the  lips  gently  rubbed  with  weakened  nitric 
acid,  become  the  seat  of  a troublesome  itching,  whilst  that 
oftentimes  though  this  acid  may  have  acted  upon  the  skin 
sufficiently  to  make  it  yellow,  it  does  not  suffer  from  it. 

The  softness  of  the  mucous  corion  makes  me  presume 
that  it  is  easily  altered  by  the  digestive  juices,  not  that  I 
confide  in  the  experiments  of  Hunter,  who  pretended 
that  these  juices  could  act  upon  the  coat  that  secretes 
them,  but  because  in  general  I have  observed  that  the 
textures  like  it  yield  very  easily  to  the  action  of  water 
in  maceration  and  are  also  very  easily  digested.  I have 
not  however  any  experiment  upon  the  subject,  and  we 
know  that  in  the  animal  economy  analogy  is  not  always 
a faithful  guide. 

All  the  mucous  surfaces,  but  especially  that  of  the 
stomach  and  intestines,  have  the  property  of  curdling 
milk,  as  have  many  other  substances,  especially  the  acids. 
Is  it  to  this  property  that  must  be  attributed  a phenome- 
non which  is  constant  during  life,  viz.  the  coagulation  of 
milk  that  enters  the  stomach  for  digestion  ? or  is  this 
phenomenon  owing  to  the  mixture  of  this  fluid  with 
those  which  are  secreted  by  the  surface  of  this  organ  ? I 
think  that  both  these  causes  contribute  to  it  at  the  same 
time , both  separate  produce  in  fact  this  phenomenon. 
Spallanzani  has  proved  it  as  it  respects  the  gastric  juices. 
Every  body  knows  that  the  mucous  membrane  dried,  and 
consequently  deprived  of  these  juices,  preserves  the  pro- 
perty of  coagulating  milk.  Spallanzani  has  convinced 


MUCOUS  SYSTEM. 


S3. 

himself  that  the  serous  and  organic  muscular  systems  of 
the  stomach  are  destitute  of  it. 

Are  aphthae  an  affection  of  the  mucous  corion  ? do  they 
belong  to  the  papillae  ? are  they  seated  in  the  glands  ? are 
they  a separate  inflammation  of  these  glands,  whilst  ca- 
tarrhs are  characterized  by  a general  inflammation  of  a con- 
siderable extent  of  the  mucous  system  ? All  these  ques- 
tions deserve  to  be  examined.  Pinel  has  perceived  the 
void  there  is  in  morbid  anatomy  upon  this  point. 

Mucous  Papillae. 

The  peculiar  kind  of  sensibility  which  the  skin  enjoys 
is  attributed  principally,  as  we  know,  to  what  is  called 
the  papillary  body,  which  commonly  is  not  easy  to  be 
demonstrated.  The  sensibility  of  the  mucous  membranes, 
somewhat  analogous  to  that  of  the  skin,  appears  to  me  to 
have  the  same  kind  of  organization,  which  is  perceived 
with  infinitely  less  ease.  The  papillae  of  this  system  can- 
not be  called  in  question  at  its  origin,  where  it  dips  into 
the  cavities,  in  the  commencement  even  of  these  cavities, 
as  upon  the  tongue,  the  palate,  the  internal  part  of  the 
alae  of  the  nose,  upon  the  glans  penis,  in  the  fossa  navi- 
cularis,  within  the  lips,  &c.  Inspection  is  sufiicient  to 
demonstrate  them  there.  But  it  is  asked  if  the  papillae 
exist  also  in  the  deep-seated  parts  of  this  system.  Analogy 
indicates  it,  since  the  sensibility  is  as  great  there  as  at 
their  origin,  though  with  varieties  that  we  shall  point 
out ; but  inspection  proves  it  in  a manner  not  less  cer- 
tain. I think  that  the  villi  with  which  we  everywhere 
see  them  covered  are  nothing  but  these  papillae. 

Very  different  ideas  have  been  entertained  of  the  nature 
of  these  villi ; they  have  been  considered  in  the  stomach 
and  the  oesophagus  as  destined  to  the  exhalation  of  the 
gastric  juice,  in  the  intestines  as  serving  for  the  absorp- 
tion of  chyle,  &c.  But,  1st,  it  is  difficult  to  conceive 
how  an  organ  everywhere  nearly  similar,  can  perform  in 


84 


MUCOUS  SYSTEM. 


different  parts  functions  so  different ; I say  nearly  similar, 
for  we  shall  see  that  these  papillae  exhibit  differences  of 
length,  size,  &c.  without  having  any  of  texture  or  struc- 
ture. 2d.  What  can  be  the  functions  of  the  villi  of  the 
pituitary  membrane,  of  the  internal  coat  of  the  urethra, 
the  bladder,  &c.  if  they  have  not  relation  to  the  sensi- 
bility of  these  membranes  ? 3d.  The  microscopical  experi- 

ments of  Leiberkuhn  upon  the  vesicle  of  the  intestinal 
villi  have  been  contradicted  by  those  of  Hunter,  of  Cruik- 
shank  and  especially  of  Hewson.  I am  certain  that  I 
have  never  seen  any  thing  similar  on  the  surface  of  the 
small  intestines,  at  the  time  of  chylous  absorption  ; and 
yet  it  would  appear  that  a thing  of  inspection  could  not 
vary.  4th.  It  is  true  that  these  intestinal  villi  are  every- 
where accompanied  by  a vascular  net-work,  which  gives 
them  a red  colour  very  different  from  the  colour  of  the 
cutaneous  papillae ; but  the  non-appearance  of  the  cuta- 
neous net-work  is  owing  to  the  pressure  of  the  atmos- 
pheric air,  and  especially  to  the  contraction  which  it  occa- 
sions in  the  small  vessels.  Observe  in  fact  the  foetus  as 
it  comes  from  the  womb  of  its  mother  ; its  skin  is  as  red 
as  the  mucous  membranes,  and  if  its  papillae  were  a little 
longer,  it  would  resemble  almost  exactly  the  internal  sur- 
face of  the  intestines.  Who  does  not  know  moreover, 
that  the  vascular  net-work  surrounding  the  cutaneous  pa- 
pillae, is  rendered  evident  by  fine  injections,  so  as  to  change 
their  colour  entirely  ? 

That  in  the  stomach  this  vascular  net-work  continuous 
with  the  exhalants  furnishes  the  gastric  juice,  and  that 
in  the  intestines  it  intermixes  with  the  origin  of  the  ab- 
sorbents, so  that  these  embrace  the  villi,  we  cannot  doubt 
after  tlie  experiments  and  observations  of  anatomists  who 
have  recently  engaged  themselves  in  investigating  the 
lymphatic  system.  But  this  does  not  prevent  the  base  of 
these  villi  from  being  nervous,  and  them  from  perform- 
ing upon  the  mucous  membranes  the  same  functions  that 


MUCOUS  SYSTEM. 


85 


the  papillse  do  upon  the  cutaneous  organ.  This  manner 
of  regarding  them  by  explaining  their  existence  generally 
observed  upon  all  the  mucous  surfaces,  appears  to  me  to 
be  much  more  conformable  to  the  plan  of  nature,  than  to 
suppose  them  in  each  place  with  different  and  often  oppo- 
site functions. 

Besides  it  is  difficult  to  decide  the  question  by  oculai* 
observation.  The  delicacy  of  these  elongations  conceals 
their  structure,  even  from  our  microscopical  instruments, 
agents  from  which  anatomy  and  physiology  do  not  ap- 
pear to  me  to  have  derived  much  assistance,  because 
when  we  see  obscurely,  each  sees  in  his  own  way  and 
according  to  his  own  wishes.  It  is  then  the  observation 
of  vital  properties  that  should  especially  guide  us ; now, 
it  is  evident  to  judge  by  them,  that  the  villi  have  the 
nature  I have  attributed  to  them.  The  following  expe- 
riment served  to  demonstrate  to  me  the  influence  of  the 
papillary  body  upon  the  cutaneous  sensibility  ; it  succeeds 
also  upon  tbe  mucous  membranes.  Remove  the  epider- 
mis in  any  part  and  irritate  the  papillary  body  with  a 
sharp  stilet ; the  animal  is  agitated,  cries  out  and  gives 
marks  of  acute  pain.  Slide  afterwards,  through  a small 
opening  made  in  the  skin,  a pointed  stilet  into  the  sub- 
cutaneous cellular  texture,  and  irritate  the  internal  surface 
of  the  corion  ; the  animal  remains  quiet  and  makes  no 
noise,  unless  some  nervous  filaments  accidentally  struck 
make  him  suffer,  fience  it  follows  very  evidently,  that 
it  is  upon  the  external  surface  of  the  skin  that  its  sensibi- 
lity resides,  that  the  nerves  pass  through  the  corion  with- 
out contributing  to  its  texture,  and  that  their  expansion 
takes  place  on  the  papillary  body.  It  is  precisely  so  with 
the  mucous  surfaces.  Observe  that  this  'Circumstance 
coincides  very  well  with  the  functions  of  the  two  sur- 
faces, which  receive  by  their  free  portion  the  action  of 
external  bodies,  to  which  they  are  foreign  by  their  ad- 
hering portion. 


86 


MUCOUS  SYSTEM. 


The  papillae  exhibit  very  great  varieties.  On  the 
tongue,  in  the  small  intestines,  in  the  stomach  and  in  the 
gall-bladder,  they  are  remarkable  for  their  length.  The 
oesophagus,  the  large  intestines,  the  bladder,  all  the  excre- 
tory ducts  have  those  that  are  less  evident ; these  last 
especially  and  the  urethra  in  particular,  are  almost  smooth 
in  their  whole  mucous  surface.  We  can  scarcely  distin- 
guish the  papillae  in  the  frontal,  sphenoidal,  maxillary 
sinuses,  &c. 

These  small  nervous  eminences  are  sufficiently  distinct 
and  separate  upon  the  tongue.  In  the  nasal  fossae,  the 
stomach  and  the  intestines,  they  are  so  near  together  and 
at  the  same  time  so  delicate,  that  the  membrane  has  at 
first  view  an  uniform  and  smooth  apppearance,  though  it 
is  covered  with  these  elongations.  Each  papilla  is  sim- 
ple ; no  bifurcation  is  ever  observed  at  its  extremity. 
All  appear  to  have  a pyramidal  form,  if  we  can  judge  at 
least  by  those  which  are  the  most  evident. 

Are  they  susceptible  of  a species  of  erection  ? It  has 
been  believed  with  regard  to  those  of  the  tongue,  which 
become  erect,  it  is.  said,  to  perceive  tastes,  and  with  re- 
gard to  those  of  the  nose,  which  receive  odours  more 
efficaciously  in  this  state  ol"  erection,  which  is  in  the  sen- 
sitive phenomena  on  a small  scale,  what  the  erection  of 
the  corpora  cavernosa  is  on  a large  one.  I do  not  believe 
that  any  exact  experiment  can  prove  this  fact.  More- 
over, it  would  be  necessary  then  that  the  intestinal,  vesi- 
cal papillae,  &c.  should  be  in  permanent  erection,  since 
they  are  almost  always  in  contact  with  foreign  substances. 

II.  Parts  common  to  the  Organization  of  the  Mucous 
System. 

\ 

Besides  the  blood  vessels,  the  exhalants  and  the  absor- 
bents which  contribute  to  the  structure  of  this  system  as 
to  that  of  all  the  others,  it  exhibits  also  a common  organ, 


MUCOUS  SYSTEM. 


87 


which  is  found  almost  always  separate  elsewhere,  but 
which  is  here  especially  designed  for  it.  This  common 
organ  is  of  a glandular  nature  ; we  shall  now  examine  it. 

Of  the  Mucous  Glands  and  of  the  Fluids  which  they 
secrete. 

The  mucous  glands  exist  in  all  the  system  of  this  name. 
Situated  beneath  the  corion  or  even  in  its  thickness,  they 
pour  out  incessantly  through  imperceptible  openings  a 
mucilaginous  fluid  which  lubricates  its  free  surface,  and 
which  defends  it  from  the  impression  of  the  bodies  with 
which  it  is  in  contact,  and  at  the  same  time  favours  the 
course  of  these  bodies. 

These  glands  are  very  apparent  in  the  bronchia,  palate, 
the  oesophagus  and  the  intestines,  in  which  they  take  the 
names  of  the  anatomists  who  have  accurately  described 
them,  and  where  they  make  in  many  places  evident  pro- 
jections upon  the  mucous  surface.  They  are  less  appa- 
rent in  the  bladder,  the  womb,  the  gall-bladder,  the  vesi- 
culse  seminales,  &c. ; but  the  mucus  that  moistens  them 
clearly  demonstrates  their  existence.  In  fact,  since  on 
the  one  hand  this  fluid  is  analogous  on  all  the  mucous  sur- 
faces, and,  on  the  other,  in  those  in  which  the  glands  are 
apparent,  it  is  evidently  furnished  by  them,  it  must  be 
secreted  in  the  same  way  in  those  in  which  the  glands  are 
less  evident.  The  identity  of  the  secreted  fluids  supposes 
in  fact  the  identity  of  the  secretory  organs.  It  appears 
that  where  these  glands  are  hidden  from  our  view,  nature 
compensates  for  their  delicacy  by  their  number.  Besides, 
there  are  animals  in  which,  in  the  intestines  especially, 
they  form  by  their  vast  number,  a kind  of  new  layer,  in 
addition  to  those  of  which  we  have  spoken.  In  man 
this  is  remarkable  in  the  palatine  arch,  in  the  pillars  of 
the  velum,  on  the  internal  surface  of  the  lips,  the  cheeks, 
&c.  &c.  There  is  then  this  great  difference  between  the 
mucous  and  the  serous  membranes,  that  the  fluid  which 


8S 


MUCOUS  SYSTEM. 


lubricates  one  is  furnished  by  secretion,  whilst  that  which 
moistens  the  others  is  from  exhalation. 

The  size  of  the  mucous  glands  varies ; those  of  the 
velum  of  the  palate,  those  of  the  mouth,  &c.  are  the 
largest ; they  become  insensible  in  the  greatest  number  of 
mucous  surfaces.  I dissected  two  subjects  that  died  of  a 
pulmonary  catarrh,  and  in  them  the  glands  of  the  trachea 
and  bronchia,  which  are,  as  we  know,  very  apparent, 
were  not  enlarged  ; the  membrane  alone  appeared  to  be 
affected.  Besides,  we  do  not  yet  know  the  injuries  of 
these  glands,  like  those  of  the  analogous  organs,  which 
are  more  apparent  from  their  size.  They  are  in  general 
of  a rounded  form  but  with  many  varieties.  No  mem- 
brane appears  to  cover  them.  They  have,  like  the  sali- 
vary glands  and  the  pancreas,  only  the  cellular  texture  for 
an  envelope.  Their  texture  is  more  dense  and  compact 
than  these  last  glands ; but  little  cellular  texture  is  found 
in  them  ; they  are  soft,  vascular,  and  appear  when  opened 
ver)'  much  like  the  prostate  gland.  I cannot  say  whether 
nerves  penetrate  them ; analogy  indicates  it,  for  all  the 
principal  glands  receive  them. 

Mucous  Fluids. 

We  know  but  little  of  the  composition  of  the  mucous 
fluids,  because  in  the  natural  state,  it  is  difficult  to  collect 
them,  and  in  the  morbid,  in  which  their  quantity  in- 
creases as  in  catarrhs  for  example,  this  composition  is 
probably  changed.  We  know’  that  in  general  they  are 
unsavoury,  insipid,  and  but  slightl}'^  soluble  in  water,  in 
that  even  which  is  raised  to  the  highest  temperature  ; 
they  become  putrid  with  difficulty.  In  fact  they  remain 
a long  time  unchanged  in  the  nose,  exposed  to  the  contact 
of  a moist  air  ; in  the  intestines,  they  serve,  without 
danger  to  them,  as  an  envelope  for  putrid  substances,  &c. ; 
taken  from  the  body  and  subjected  to  different  experi- 
jnents,  they  give  results  conformable  to  these  facts.  All 


Ml/COUS  SYSTEM. 


89 


the  acids  act  upon  them  and  coIouf  them  differently  ; ex- 
posed to  a dry  air,  they  thicken  by  evaporation,  and  are 
often  even  reduced  to  small  shining  laminae.  The  nasal  mu- 
cus especially  exhibits  this  phenomenon.  Fourcroy  has 
given  in  detail  the  analysis  of  this  mucus ; he  has  also 
given  that  of  the  tracheal  mucus.  But  we  must  not  apply 
rigorously  to  the  analogous  fluids  our  knowledge  of  the 
composition  of  these.  It  is  sufficient  in  fact  to  examine 
a certain  number  of  these  fluids,  to  be  convinced  that  they 
are  not  the  same  in  any  two  places,  that  more  or  less 
thick,  more  or  less  uniform,  different  in  their  colour, 
their  odour  even,  &c.  they  vary  in  the  principles  that 
constitute  them,  as  the  membranes  which  furnish  them 
vary  in  their  structure,  in  the  number  and  size  of  their 
glands,  in  the  thickness  of  their  corion,  the  form  of  their 
papillae,  the  state  of  their  vascular  and  nervous  systems, 
&c.  I am  far  from  being  certain  that  the  gastric  juice  is 
a mucous  juice ; it  is  even  probable  that  exhalation  fur- 
nishes it,  the  glands  of  the  stomach  throwing  out  a differ- 
ent fluid  by  the  way  of  secretion.  But  this  assertion  is 
not  accurately  demonstrated,  and  perhaps  hereafter  it  will 
be  proved  that  this  juice,  so  difierent  from  the  other  mu- 
cous juices,  is  however  one  of  them,  and  that  its  proper- 
ties are  distinct  only  because  the  structure  of  the  mucous 
surface  of  the  stomach  is  not  the  same  as  that  of  the  other 
analogous  surfaces. 

The  functions  of  the  mucous  fluids  in  the  animal  econo- 
my are  not  ambiguous.  The  first  of  these  functions  is  to 
defend  the  mucous  membranes  from  the  impression  of 
the  bodies  with  which  they  are  in  contact,  and  all  which, 
as  we  have  observed,  are  heterogeneous  to  that  of  the  ani- 
mal. These  fluids  form  upon  their  respective  surfaces  a 
layer  which  supplies,  to  a certain  extent,  by  its  extreme 
tenuity,  the  absence  of  their  epidermis.  Thus  where-this 
membrane  is  very  apparent,  as  upon  the  lips,  the  glans 
VOL.  in.  12 


•JO 


MUCOUS  SYSTE^f. 


penis,  at  the  entrance  of  the  nose  and  in  general  at  all  the 
origins  of  the  mucous  system,  these  fluids  are  not  very 
abundant.  The  skin  has  only  an  oily  la}^er,  infinitely  less 
evident  than  the  mucous  of  which  we  are  treating,  be- 
cause its  epidermis  is  very  distinct. 

This  use  of  the  mucous  fluids  explains  why  they  are 
more  abundant  where  heterogeneous  bodies  remain  some 
time,  as  in  the  bladder,  at  the  extremity  of  the  rectum, 
&c.  than  where  these  bodies  are  only  to  pass,  as  in  the 
ureters,  and  the  excretory  ducts  generally. 

Hence  why  when  the  impression  of  a body  would  be 
injurious,  these  fluids  are  poured  out  in  greater  quantity 
upon  their  surfaces.  The  sound  ^Yhich  enters  the  urethra 
and  remains  in  it,  the  instrument  that  is  left  in  the  vagina 
to  compress  a polypus,  that  which  remains  some  time 
with  the  same  view  in  the  nasal  fossae,  the  canal  fixed  in 
the  lachrymal  sac  to  remove  the  obstruction,  that  which 
is  introduced  into  the  oesophagus  to  assist  interrupted 
deglutition,  always  produce,  upon  the  portions  of  the  mu- 
cous surface- that  corresponds  to  them,  a more  abundant 
secretion  of  the  fluid  which  is  constantly  poured  out,  a 
true  catarrh.  This  is  one  of  the  principal  reasons  that 
renders  it  difficult  to  keep  elastic  sounds  in  the  wind-pipe. 
The  abundance  of  the  mucus  that  is  then  secreted,  by 
closing  the  openings  in  the  instrument,  renders  frequent 
introductions  necessary,  and  can  even  threaten  the  patient 
with  suffocation,  as  Desault  himself  has  observed,  though 
however  he  obtained  great  advantage  from  this  means,  as 
I have  shown  in  his  surgical  works.  I ought  even  to  say, 
that  since  the  publication  of  the  Treatise  on  the  Mem- 
branes, I attempted  to  fix  a sound  in  the  air  tube  of  a dog, 
and  that  the  animal  died  at  the  end  of  some  time,  having 
the  bronchia  filled  with  a frothy  fluid  which  appeared  to 
have  suffocated  him. 

It  appears  then  that  every  considerable  excitement  of 
the  mucous  surfaces  produces  a remarkable  increase  of 


MUCOUS  SYSTEM. 


SI 


action.  But  how  can  this  excitement,  which  does  not 
take  place  immediately  upon  the  gland,  have  so  great  an 
influence  upon  it  ? for,  as  we  have  said,  these  glands  are 
always  under  the  membrane,  and  consequently  separated 
by  it  from  the  irritating  bodies.  It  appears  that  it  is 
owing  to  a general  modification  of  the  glandular  sensi- 
bility, which  is  capable  of  being  brought  into  action  by 
any  irritation  upon  the  extremity  of  the  excretory  ducts, 
as  I shall  prove  in  the  glandular  system. 

It  is  to  the  susceptibility  that  the  mucous  glands  have 
of  feeling  the  irritation  made  at  the  extremity  of  their 
ducts,  that  must  be  referred  the  artificial  catarrhs  with 
which  Vauquelin  has  been  affected  by  respiring  the 
vapours  of  the  oxy-muriatic  acid,  the  mucous  discharge 
that  attends  the  presence  of  a polypus,  of  any  tumour  in 
the  vagina,  of  a stone  in  the  bladder,  &c.  the  frequency 
of  fluor  albus  in  women  who  are  immoderate  in  the  use 
of  sexual  intercourse,  the  more  abundant  discharge  of  the 
mucus  from  the  nostrils  of  those  who  take  snuff,  &c. 
In  all  these  cases,  there  is  evidently  excitement  at  the 
extremity  of  the  mucous  ducts.  I refer  also  to  this  ex- 
citement the  mucous  discharge  that  takes  place,  from 
stimulating  the  end  of  the  nipple  of  a woman  who  does 
not  give  suck,  the  copious  secretions  which  the  presence 
of  an  irritating  body  produces  in  the  intestines,  secretions 
which  especially  furnish  the  matter  of  diarrhoeas,  the 
gastric  derangements  which  succeed  an  indigestion  that 
has  allowed  to  remain  on  the  mucous  surface  of  the 
stomach  substances  not  digested  and  consequently  irri- 
tating ; these  derangements  are  in  fact  real  catarrhs  of  the 
membrane  of  the  stomach,  catarrhs  which  most  often  are 
not  connected  with  bilious  turgescence.  I could  add 
many  other  examples  of  the  mucous  secretions  increased 
by  an  irritation  upon  the  surface  of  tlie  membranes,  at 
the  extremity  of  the  excretory  ducts ; these  will  be  suf- 
ficient to  give  an  idea  of  the  others. 


92 


MUCOUS  SYSTEM. 


AH  these  excitements  produce  a kind  of  inflammation, 
the  peculiarity  of  which  is  to  contract  at  first  for  some 
time  the  glandular  ducts,  and  arrest  the  secretion,  which 
they  afterwards  excite  in  great  quantity.  When  the 
mdcous  fluids  have  flowed  abundantly  for  some  time,  they 
gradually  diminish  though  the  cause  continues ; thus  less 
mucus  is  discharged  from  the  urethra  in  proportion  after 
the  sound  has  remained  in  it  a month,  than  when  first  intro- 
duced ; but  almost  always  as  long  as  the  cause  continues, 
the  mucous  discharge  is  greater  than  in  a natural  state. 

Blisters  are  much  employed  in  medicine  on  the  cuta- 
neous organ,  to  dispel,  according  to  some,  the  morbific 
humour,  and  overcome,  according  to  others,  a natural 
irritation  by  an  artificial  one.  Why  should  we  not  also 
in  many  cases  irritate  the  mucous  surfaces  ? wdiy  not  act 
upon  the  pituitary  membrane,  upon  the  glans  penis,  upon 
the  membrane  of  the  urethra,  upon  the  pharynx,  &c.  and 
especially  upon  the  uvula  which  is  so  sensible  ? why,  in- 
stead of  epispastics  upon  the  perineum  and  sacrum,  should 
we  not  introduce  a sound  into  the  urethra  for  a paralysis 
of  the  bladder  ? Instead  of  acting  in  hemiplegia  upon 
the  cutaneous  organ,  I have  already  twice  employed  the 
following  means;  I have  introduced  a sound  into  the 
urethra,  one  in  each  nasal  fossa,  and  at  the  same  time,  a 
surgeon  irritated  at  intervals  the  uvula ; the  patients  ap- 
j)eared  to  be  much  more  excited  than  by  blisters.  Very 
strong  purgative  enemas  and  emetics  prove  the  advantage 
of  the  excitement  of  the  mucous  membranes  in  this  case. 
Would  it  not  often  be  better  in  ophthalmia,  to  produce  an 
artificial  catarrh  in  the  nostril  of  the  diseased  side,  than  to 
put  a blister  or  seton  in  the  neck  ? I have  once  tried  it ; 
it  did  not  succeed  ; but  the  ophthalmia  was  of  long  stand- 
ing ; I propose  to  repeat  these  experiments  at  the  Hotel 
Dieu  upon  a great  number  of  patients.  I think  that  we 
might  often  in  diseases  make  use  of  mucous  excitements 
instead  of  cutaneous,  with  much  more  advantage,  because 


MUCOUS  SYSTEM. 


93 


in  the  mucous  system  the  contact  of  a body  is  sufficient, 
and  it  is  not  necessary  to  produce,  by  removing  the  epi- 
dermis, a kind  of  ulcer. 

The  mucous  membranes  by  the  continual  secretion  of 
which  they  are  the  seat,  enjoy  a principal  part  in  the  ani- 
mal economy.  We  ought  to  consider  them  as  one  of  the 
great  emunctories  by  which  the  residue  of  nutrition  con- 
stantly escapes,  and  consequently  as  one  of  the  principal 
agents  of  the  habitual  decomposition  which  removes  from 
living  bodies  the  particles  that,  having  for  some  time  con- 
tributed to  the  composition  of  the  solids,  are  afterwards 
to  become  heterogeneous  to  them.  Observe  in  fact  that 
the  mucous  fluids  do  not  enter  the  circulation,  but  go  out 
of  the  body ; that  of  the  bladder,  the  ureters  and  the 
urethra,  with  the  urine ; that  of  the  vesiculs  seminales 
and  the  difierent  ducts  with  the  semen ; that  of  the  nos- 
trils by  the  act  of  blowing  the  nose  ; that  of  the  mouth, 
in  part  by  evaporation  and  in  part  by  the  anus  with  the 
excrements  ; that  of  the  bronchia,  by  pulmonary  exhala- 
tion, which  arises  principally,  as  I shall  say,  from  the 
solution  of  this  mucous  fluid  in  the  inspired  air  ; those  of 
the  oesophagus,  the  stomach,  the  intestines,  the  gall-blad- 
der, &c.  with  the  excrements,  of  which  they  often  form 
in  the  ordinary  state  a part  almost  as  considerable  as  the 
residue  of  the  aliments,  and  which  they  even , compose 
almost  entirely  in  some  cases  of  dysentery  and  fever,  in 
which  the  quantity  of  matter  voided  is  evidently  dispro- 
portioned  to  that  taken  in,  &c.  Let  us  observe  upon  this 
subject  that  there  are  always  some  errors  in  the  analyses 
of  the  fluids  in  contact  with  the  membranes  of  which  we 
are  speaking,  as  in  that  of  the  urine,  the  bile,  the  gastric 
juices,  &c.  because  it  is  very  difficult  and  even  impossible 
to  separate  the  mucous  fluids  from  them. 

If  w'e  recollect  what  has  been  previously  said  upon  the 
extent  of  the  two  general  mucous  surfaces,  wliich  is  equal 
and  even  superior  to  the  extent  of  the  cutaneous  organ, 


MUCOUS  SYSTEM. 


‘)4 

and  if  we  afterwards  consider  that  these  two  great  sur- 
faces are  constantly  throwing  out  mucous  fluids,  we  shall 
perceive  how  important  this  evacuation  must  be  in  the 
economy,  and  of  what  mischief  its  derangement  must  be- 
come the  source.  It  is  undoubtedly  to  this  law  of  nature 
which  wishes  to  have  every  mucous  fluid  thrown  out, 
that  must  be  attributed,  in  part  in  the  foetus,  the  presence 
of  the  unctuous  fluid  of  which  the  gall-bladder  is  full, 
the  meconium  which  loads  the  intestines,  &c.  fluids  which 
appear  to  be  but  a mass  of  mucous  juices,  which  being 
unable  to  pass  off",  remain  until  birth,  without  being  ab- 
sorbed, upon  the  respective  organs  on  which  they  have 
been  secreted. 

The  mucous  fluids  are  not  the  only  ones  that  are  thrown 
out,  and  are  in  this  way  excrementitious  substances  to 
the  economy  ; this  is  the  case  with  almost  all  the  fluids 
separated  from  the  mass  of  blood  by  secretion  ; this  is 
evident  as  it  I’espects  the  greatest  part  of  the  bile ; prob- 
ably the  saliva,  the  pancreatic  juice  and  the  tears  are  also 
thrown  out  with  the  excrements,  and  their  colour  alone 
prevents  them  from  being  distinguished  like  the  bile.  I 
do  not  even  know  if,  by  reflecting  on  many  phenomena, 
we  might  not  attempt  to  establish  as  a general  principle, 
that  every  fluid  separated  by  secretion  does  not  enter  the 
circulation  again,  that  this  phenomenon  belongs  only  to 
the  fluids  separated  by  exhalation,  as  those  of  the  serous 
cavities,  of  the  articulations,  of  the  cellular  texture,  of 
the  medullary  organ,  &c.  ; that  all  the  fluids  are  thus 
either  excrementitious  or  recrementitious,  and  that  no 
one  is  excremento  recrementitious  as  the  common  division 
implies.  The  bile  in  the  gall-bladder,  the  urine  in  the 
bladder,  the  semen  in  the  vesiculae  seminales,  are  cer- 
tainly absorbed  ; but  it  is  not  the  fluid  itself  which  re- 
enters the  circulation  ; it  is  only  its  most  delicate  parts, 
some  of  its  principles  which  w'e  do  not  exactly  know, 
probably  the  serous  and  l_vmphatic  part;  this  does  not  re» 


MUCOUS  SYSTEM. 


95 


aemble  the  absorption  of  the  pleura  and  other  analogous 
membranes,  in  which  the  fluid  re-enters  the  blood  as  it 
came  out  of  it. 

That  which  is  certain  on  the  subject  of  the  excretion 
of  the  secreted  fluids  is,  that  I have  never  been  able  to 
produce  absorption  of  the  bile  by  the  lymphatics  by  in- 
jecting it  into  the  cellular  texture  of  an  animal ; it  pro- 
duces there  inflammation  and  afterwards  suppuration. 
We  know  that  urine  efl'used  is  not  absorbed  and  that  it 
destroys  every  part  it  touches,  whilst  that  eflusions  of 
lymph  and  blood  are  easily  discussed.  There  is  as  it  re- 
spects the  composition  an  essential  difference  between  the 
hlood  and  the  secreted  fluids.  The  exhaled  fluids  on  the 
contrary,  as  the  serum,  in  this  respect  resemble  it  very 
much. 

Another  very  evident  proof  that  all  the  mucous  fluids 
are  designed  to  be  thrown  out,  is,  that  when  they  have 
continued  for  some  time  in  any  quantity  upon  their  re- 
spective surfaces,  they  create  there  a painful  sensation  of 
which  nature  relieves  us  by  various  means.  Thus  the 
cough,  which  is  the  constant  result  of  an  accumulation  of 
mucus  in  the  bronchia,  serves  to  expel  it ; thus  vomiting 
in  gastric  derangements  answers  the  same  purpose  as  it 
respects  the  mucous  juices  accumulated  in  the  stomach, 
whose  presence  produces  a weight  and  even  pain,  though 
the  membranes  be  not  affected.  We  cough  at  will,  be- 
cause it  is  the  diaphragm  and  intercostals  by  which  this 
function  is  performed ; we  do  not  seek  in  medicine  for 
any  means  to  excite  it.  But  as  we  cannot  vomit  at  will, 
and  as  the  presence  of  mucous  juices  often  by  fatiguing 
the  stomach,  does  not  irritate  it  sufficiently  to  produce  a 
contraction,  art  has  recourse  to  various  emetics.  We 
know  what  a painful  sensation  of  weight  the  continuance 
of  mucus  accumulated  in  the  frontal,  maxillary,  sinuses, 
&c.  occasions,  when  there  is  a catarrh  of  a portion  of  the 
pituitary  membrane.  The  region  of  the  bladder  is  for 


91) 


MUCOUS  SYSTEM, 


the  same  reason,  in  catarrhs  of  this  organ,  the  seat  of  a 
troublesome  and  even  painful  sensation. 

In  general,  the  sensation  which  arises  from  the  presence 
of  the  mucous  juices  remaining  too  long  and  in  too  great 
quantity  upon  their  respective  surfaces,  varies  because,  as 
we  shall  see,  each  part  of  the  mucous  system  has  its  pecu- 
liar mode  of  sensibility  ; so  that  the  pain  is  not  the  same 
in  each,  though  produced  by  the  same  cause.  I would 
only  observe  that  this  sensation  does  not  resemble  that 
which  arises  from  the  tearing  or  the  acute  irritation  of 
our  parts ; it  is  an  uneasy,  inconvenient  sensation,  diffi- 
cult to  be  borne.  Every  one  knows  that  which  arises 
from  mucus  accumulated  in  the  nasal  fossae,  when  the 
nose  has  not  been  blown  for  a long  time,  that  disagreeable 
one  that  accompanies  gastric  derangements,  &c.  Those 
who  have  a weakness  of  the  lachrymal  sac  in  which  the 
tears,  on  account  of  this,  accumulate  during  the  night, 
wake  up  with  a sensation  of  weight,  of  which  they  are 
relieved  by  evacuating  the  sac  by  pressure,  if  the  puncta 
lachrymalia  are  open. 

Blood  Vessels. 

The  mucous  membranes  receive  a very  great  number 
of  vessels.  The  remarkable  redness  that  distinguishes 
them  would  be  sufficient  to  prove  it,  if  injections  did  not 
demonstrate  it ; this  redness  is  not  everywhere  uniform. 
It  is  almost  nothing  in  the  sinuses  of  the  face,  in  the  in- 
ternal ear,  of  which  the  membranes  are  rather  whitish, 
and  which  appear  so  especially,  because  their  extreme 
delicacy  allows  the  bone  upon  which  they  are  applied 
to  be  seen  very  distinctly.  In  the  bladder,  in  the  great 
intestines,  in  the  excretories,  &c.  this  colour,  though  still 
very  pale,  is  a little  more  evident ; it  becomes  very  much 
so  in  the  stomach,  the  small  intestines,  the  vagina  and  in 
the  pituitary  and  palatine  membranes.  In  the  gall-blad- 


MUCOUS  SYSTEM. 


97 


der  we  cannot  distinguish  it,  because  the  bile  always 
covers  the  mucous  surface  in  the  dead  body. 

This  colour  depends  upon  a very  extensive  vascular  net- 
work, the  branches  of  which,  after  having  passed  through 
the  mucous  corion,  and  ramifying  there,  divide  and  spread 
ad  infinitum  on  its  surface,  embracing  the  papillary  body 
and  covered  only  by  the  epidermis. 

It  is  the  superficial  position  of  these  vessels  and  con- 
sequently their  want  of  support  on  one  side,  that  exposes 
them  frequently  to  ruptures  from  considerable  shocks,  as 
happens  on  the  surface  of  the  bronchia  from  a severe 
cough,  on  that  of  the  ear  and  the  nose  from  a violent 
blow  on  the  head  We  know  that  hemorrhage  of  the 
mucous  system  bordering  oil  the  brain,  is  a common  acci- 
dent from  concussions  and  wounds  of  the  head.  Hence 
why  the  least  gravel  makes  the  ureters  bleed ; why  one 
of  the  signs  of  stone  in  the  bladder  is  the  passing  of  blood  ; 
why  a blunt  sound  carefully  introduced  is  so  often  with- 
drawn bloody  from  the  urethra;  why  the  least  effort 
made  with  instruments  carried  upon  polypi,  into  a fistula 
lachrymalis  or  into  the  nostrils,  produces  hemorrhage.  I 
have  already  observed  that  we  must  carefully  distinguish 
these  hemorrhages  from  those  furnished  by  the  exhalants, 
and  which  do  not  suppose  any  vascular  rupture. 

It  is  also  the  superficial  position  of  the  vessels  of  the 
mucous  system,  which  makes  its  portions  visible,  as  the 
red  edge  of  the  lips,  the  glans  penis,  &c.  often  serve  to 
show  us  the  state  of  the  circulation.  Thus  in  the  different 
species  of  asphyxia,  in  submersion,  strangulation,  &c. 
these  parts  are  remarkably  livid,  an  effect  of  the  passage 
of  the  venous  blood,  which  has  undergone  no  change  from 
the  want  of  respiration,  into  the  extremities  of  the  arterial 
system. 

The  long  continued  exposure  of  the  mucous  system  to 
the  air,  often  makes  it  lose  the  redness  that  characterizes 
13 


VOL.  III. 


93 


MUCOUS  SYSTEM. 


il:,  and  it  then  assumes  the  appearance  of  the  skin,  as  has 
been  observed  by  Sabatier  in  treating  of  prolapsus  of  the 
womb  and  vagina,  which,  from  this  circumstance,  have 
sometimes  so  misled  some  people,  as  to  make  them  be- 
lieve it  a case  of  hermaphrodism. 

An  important  question  presents  itself  in  the  history 
of  the  vascular  system  of  the  mucous  membranes,  viz. 
whether  this  system  admits  more  or  less  blood  according 
to  different  circumstances.  As  the  organs  within  which 
these  membranes  are  spread,  are  almost  all  susceptible  of 
contraction  and  dilatation,  as  we  see  in  the  stomach,  the 
intestines,  the  bladder,  &c.  it  has  been  thought  that  during 
the  dilatation,  the  vessels  being  more  expanded,  receive 
more  blood,  and  that  during  the  contraction  on  the  con- 
trary, being  folded  up,  as  it  were  choaked,  they  admit 
but  a small  quantity  of  this  fluid  which  then  flows  into 
the  neighbouring  organs.  Chaussier  has  made  an  appli- 
cation of  these  principles  to  the  stomach,  whose  circula- 
tion he  has  considered  as  being  alternately  inverse  of  that 
of  the  omentum,  which  receives  during  the  vacuity  of 
this  organ,  the  blood  which  this  when  it  is  contracted 
cannot  admit.  An  analogous  use  has  also  been  attributed 
to  the  spleen  since  the  time  of  Lieutaud.  The  following 
is  what  the  inspection  of  animals  opened  during  abstinence 
and  at  different  periods  of  digestion,  has  shown  me  upon 
this  point. 

1st.  During  the  fulness  of  the  stomach  the  vessels  are 
more  apparent  on  the  exterior  of  this  viscus,  than  when 
it  is  empty.  Within,  the  mucous  surface  is  not  more 
red,  sometimes  it  has  appeared  to  me  to  be  less  so.  2d. 
The  omentum,  less  extended  during  the  fulness  of  the 
stomach,  exhibits  nearly  the  same  number  of  vessels,  as 
long,  but  more  tortuous,  than  when  it  is  empty.  If  they 
contain  less  blood,  the  difference  is  hardly  sensible.  I 
would  observe,  that  in  order  to  distinguish  this  well,  it 
is  necessary  to  take  care  that  in  opening  the  animal,  the 


MUCOUS  SYSTEM. 


99 


blood  does  not  fall  on  the  omentum  which  presents  itself, 
and  thus  prevent  its  state  from  being  ascertained.  This 
is  besides  a necessary  consequence  of  the  arrangement  of 
the  vascular  system  of  the  stomach.  In  fact  the  great 
stomachic  coronary  being  situated  transversely  between 
it  and  the  omentum,  and  furnishing  branches  to  each,  it 
is  evident  that  when  the  stomach  is  lodged  between  the 
layers  of  the  omentum  by  separating  these  layers,  and 
this  by  applying  itself  npon  it  becomes  shorter ; it  is 
evident,  I say,  that  the  branches  which  it  receives  from 
the  coronary  cannot  be  equally  applied  to  it  also.  In 
order  to  this,  it  would  be  necessary  that  they  should  go 
from  one  to  the  other  without  the  intermediate  trunk 
that  cuts  them  at  right  angles  ; then,  in  distending,  the 
stomach  would  separate  them  as  it  does  the  omentum, 
and  would  be  lodged  between  them ; whereas  it  pushes 
them  before  it  with  their  common  trunk,  the  stomachic 
coronary,  and  makes  them  fold.  3d.  I am  confident  that 
there  is  no  such  constant  relation  between  the  size  of  the 
spleen  and  the  emptiness  or  fulness  of  the  stomach,  and 
that  these  two  circumstances  coincide  necessarily,  and  that 
if  the  first  organ  increases  or  diminishes  under  diflferent 
circumstances,  it  is  not  always  precisely  the  reverse  of 
the  stomach.  I first  made,  like  Lieutaud,  experiments 
upon  dogs  to  convince  myself  of  it ; but  the  inequality  in 
the  size  and  age  of  those  that  were  brought  to  me,  making 
me  fear  that  I should  not  be  able  to  compare  their  spleens 
correctly,  I repeated  them  upon  guinea-pigs  of  the  same 
litter  and  size,  and  examined  at  the  same  time,  some 
when  the  stomach  was  empty  and  others  when  it  was 
full.  I have  almost  always  found  the  size  of  the  spleen 
nearly  equal,  or  at  least  the  difference  was  not  very  sen- 
sible. Yet  in  other  experiments,  I have  seen  under 
various  circumstances,  inequalities  in  the  size  of  the  spleen 
and  especially  in  the  weight  of  this  viscus ; but  it  was 
indifferently  during  or  after  digestion. 


100 


MUCOUS  SYSTEM. 


It  appears  from  all  this,  that  if  during  the  vacuity  of 
the  stomach,  there  is  a reflux  of  blood  towards  the  omen- 
tum and  spleen,  this  reflux  is  less  than  it  has  been  com- 
monly said  to  be.  Besides  during  this  state  of  vacuity, 
the  numerous  folds  of  the  mucous  membrane  of  this 
viscus  leaving  it,  as  we  have  said  above,  almost  as  much 
surface  and  consequently  as  many  vessels  as  during  ful- 
ness, the  blood  can  circulate  in  it  almost  as  freely.  It 
has  no  real  obstacles  but  in  the  tortuous  courses,  and  not 
in  the  obstruction,  compression  and  choaking  of  these 
vessels  by  the  contraction  of  the  stomach  ; now  this  ob- 
stacle is  easily  surmounted,  or  rather  it  is  not  one  as  I 
have  proved  in  my  Researches  upon  Death.  As  to  the 
other  hollow  organs,  it  is  difficult  to  examine  the  circu- 
lation of  the  neighbouring  parts  during  their  fulness 
and  vacuity,  as  the  vessels  of  these  are  not  superficial 
as  in  the  omentum,  and  as  they  themselves  are  not  insu- 
lated like  the  spleen.  We  can  only  then,  to  decide  the 
question,  see  the  state  of  the  mucous  membranes  on  their 
internal  face  ; now  this  face  has  always  appeared  to  me  to 
be  as  red  during  the  contraction  as  during  the  dilatation. 

Besides  I only  give  this  as  a fact  without  pretending 
to  draw  from  it  any  consequence  in  opposition  to  the  com- 
mon opinion.  It  is  possible  in  fact  that  though  the  quan- 
tity of  blood  may  be  nearly  always  the  same,  the  rapidity 
of  the  circulation  being  increased,  more  of  this  fluid  may 
consequently  in  a given  time  enter  it  when  it  is  full ; which 
appears  to  be  necessary  to  the  greater  secretion  that  then 
takes  place  of  the  mucous  fluids,  a secretion  excited  by 
the  presence  of  the  substances  in  contact  with  the  surfaces 
of  the  same  name.  For  example,  there  is  no  doubt  that 
there  is  three  or  even  four  times  as  much  mucus  secreted 
in  the  urethra,  when  a sound  fills  it,  as  when  it  is  empty ; 
now  the  blood  must  be  in  proportion. 

The  remarkable  redness  of  the  mucous  system,  the 
analogy  of  respiration  in  which  the  blood  flows  through 


MUCOUS  SYSTEM, 


101  • 


the  mucous  surface  of  the  bronchia  the  well  known  ex- 
periment of  a bladder  filled  with  blood  and  immersed  in 
oxygen,  by  which  means  the  blood  becomes  red,  have 
induced  a belief  that  the  blood  being  separated  from  the 
atmospheric  air  only  by  a thin  pellicle  or  some  of  the 
mucous  surfaces,  as  upon  the  pituitary,  the  palatine,  the 
glans  penis,  &c.  assumed  there  a redder  colour,  either  from 
getting  rid  of  a portion  of  its  carbonic  acid  gas,  or  by 
combining  with  the  oxygen  of  the  air,  and  that  these 
membranes  thus  performed  functions  accessory  to  those 
of  the  lungs.  The  experiments  of  Jurine  upon  the  cuta- 
neous organ,  experiments  adopted  by  many  celebrated 
philosophers,  seem  to  strengthen  this  conjecture. 

I tried  the  following  experiment  to  ascertain  this  fact. 
I drew  through  a wound  made  in  the  abdomen  a portion 
of  intestine  which  I tied  at  one  point,  I afterwards  reduced 
it,  keeping  out  a small  portion  only  which  I opened  and 
by  which  I introduced  atmospheric  air,  which  filled  the 
whole  portion  situated  on  this  side  of  the  ligature.  I 
afterwards  tied  the  intestine  below  the  opening,  and  re- 
duced the  whole  of  it.  At  the  end  of  an  hour,  the 
animal  being  opened,  I compared  the  blood  of  the  mesen- 
teric veins  which  arose  from  the  portion  of  intestine  dis- 
tended with  air,  with  the  blood  of  the  other  mesenteric 
veins  arising  from  the  rest  of  the  canal.  No  difference 
of  colour  was  manifest ; the  internal  surface  of  the  dis- 
tended portion  of  the  intestine  was  not  of  a more  brilliant 
red.  I thought  I should  obtain  a more  evident  effect,  by 
repeating  with  oxygen  the  same  experiment  upon  another 
animal ; but  I perceived  no  greater  variety  in  the  colour 
of  the  blood.  As  upon  tbe  mucous  membranes  which 
are  ordinarily  in  contact  with  the  air,  this  fluid  is  con- 
stantly changing  and  is  agitated  by  a perpetual  motion, 
and  as  in  the  preceding  experiment  it  remained  stagnant, 
I attempted  to  produce  the  same  effect  in  the  intestines. 
I made  two  openings  in  the  abdomen,  and  drew  out  at 


102 


MUCOUS  SYSTEM. 


each  a portion  of  the  intestinal  canal, ; having  opened  these 
two  portions,  I fitted  to  one  the  tube  of  a bladder  full  of 
oxygen  and  to  the  other  that  of  an  empty  bladder ; I after- 
wards compressed  the  full  bladder,  so  as  to  make  the 
oxygen  pass  into  the  other,  by  going  through  this  portion 
of  intestine,  left  in  the  abdomen  that  the  heat  might  sup- 
port the  circulation  in  it.  The  oxygen  was  thus  many 
times  sent  from  one  bladder  to  another,  taking  its  course 
through  the  intestine,  which,  on  account  of  its  contrac- 
tility is  more  difficult  than  it  at  first  seems  to  be.  The 
abdomen  being  afterwards  opened  I found  no  difference 
between  the  venous  blood  returning  from  this  poi’tion  of 
intestine,  and  that  which  flowed  from  the  others.  The 
superficial  position  of  the  mesenteric  veins,  covered  only 
by  a fine  and  transparent  layer  of  peritoneum,  their  size, 
if  the  animal  be  rather  large,  render  this  sort  of  com- 
parison very  easy. 

I perceive  that  we  cannot  infer  from  what  takes  place 
in  the  intestines,  what  happens  in  the  pituitary,  palatine 
membrane,  &c.  because  though  analogous,  the  organiza- 
tion may  be  different.  We  cannot  here  as  in  the  intes- 
tines examine  the  venous  blood  returning  from  the  part ; 
but,  1st,  if  we  consider  that  in  animals  who  have  respired 
oxygen  for  some  time,  we  see  the  palatine  and  pituitary 
membranes  more  red  ; 2d,  if  we  reflect  that  the  lividity 
of  the  different  parts  of  this  membrane,  in  those  destroyed 
by  aspli3'xia  bj"  the  carbonic  acid  gas,  depends  not  on  the 
immediate  contact  of  this  gas  upon  the  membrane,  but 
upon  the  passage  of  venous  blood  into  the  arterial  system, 
as  my  experiments  have,  I think,  demonstrated  ; 3d,  if 
we  remark  finally  that  in  these  circumstances  the  con- 
tact of  the  air  does  not  change,  after  death,  the  lividity 
which  the  venous  blood  gives  to  the  mucous  membranes, 
although  the  skin  be  then  much  more  permeable  to  every 
kind  of  aeriform  fluid  ; we  shall  see  that  it  is  at  least 
necessary  to  suspend  our  judgment  upon  the  colouring  of 


MUCOUS  SYSTEM. 


103 


the  blood  in  the  mucous  membranes,  until  further  obser- 
vations have  decided  the  question. 

The  following  experiment  may  also  throw  some  light 
upon  the  subject.  I have  inflated  the  peritoneal  cavity  of 
several  guinea-pigs  with  carbonic  acid  gas,  with  hydro- 
gen, oxygen  and  atmospheric  air,  to  see  if  I could  efiect 
through  a serous  membrane  what  I could  not  make  succeed 
in  a mucous ; I have  not,  after  these  experiments,  found 
any  difference  in  the  colour  of  the  blood  of  the  abdominal 
system  ; it  was  always  the  same  as  in  the  common  guinea- 
pig  which  I killed  for  comparison. 

I think  however  that  I have  remarked  many  times, 
both  in  frogs  and  animals  with  red  and  warm  blood,  such 
as  cats  and  guinea-pigs,  that  the  infiltration  of  oxygen  into 
the  cellular  texture  gives,  at  the  end  of  some  time,  a 
much  brighter  colour  to  the  blood,  than  that  which  this 
fluid  exhibits  in  artificial  emphysemas  produced  by  car- 
bonic acid  gas,  hydrogen  and  atmospheric  air,  in  all  which 
the  colour  of  the  blood  scarcely  differ  at  all  from  what 
is  natural.  But  in  other  cases  oxygen  has  had  no  influ- 
ence upon  the  colour  of  the  blood ; so  that  notwithstand- 
ing having  made  many  experiments  upon  this  point,  I am 
unable  to  give  any  general  result.  It  appears  that  the 
tonic  forces  of  the  cellular  texture  and  of  the  parietes  of 
the  vessels  which  are  spread  upon  this  texture,  receive  a 
very  variable  influence  from  the  contact  of  the  gases,  and 
that  according  to  the  nature  of  this  influence,  the  fibres 
crisping  and  contracting  more  or  less,  render  these  parts 
more  or  less  permeable,  either  to  the  aeriform  fluids  that 
tend  to  escape  from  the  blood  in  order  to  unite  with  that  of 
the  emphysema,  or  to  this  last  fluid,  if  it  tends  to  combine 
with  the  blood,  which  no  doubt  produces  the  varieties  I 
have  observed. 

The  red  colour  of  the  mucous  system  is  analogous  to 
that  of  the  muscular  system.  It  does  not  depend  essen- 
tially on  the  blood  circulating  in  the  small  arteries  of  this 


104 


MUCOUS  SYSTEM. 


system.  It  arises  from  the  colouring  portion  of  the  blood 
combined  with  the  mucous  texture,  especially  in  the  deep 
part  of  the  organs  ; for  at  the  origin  of  the  mucous  sur- 
faces, this  colour  appears  to  be  principally  owing  to  the 
blood  in  circulation  ; in  fact  asphyxia  does  not  render 
so  livid  the  deep  mucous  surfaces,  as  it  does  those  which 
are  superficial  and  in  communication  with  the  skin.  The 
black  blood  arrives  immediately  to  these  by  the  last  arte- 
ries, and  tinges  them  as  we  see.  In  syncope  in  which 
the  heart  being  affected  no  longer  sends  blood  into  the 
arteries,  we  know  that  this  portion  of  the  mucous  system 
becomes  instantly  white. 

Besides  the  red  colour  of  the  deeper  portions,  can,  like 
that  of  the  muscles,  be  removed  by  repeated  washing  and 
frequently  changing  the  water.  Yet  the  water  in  which 
they  have  been  washed  is  not  as  red  as  that  used  for  the 
muscles. 

The  instant  a mucous  surface  is  plunged  into  boiling 
water,  however  red  it  may  be,  as  that  of  the  intestines 
and  the  stomach,  it  instantly  whitens.  The  action  of  the 
nitric,  sulphuric  and  muriatic  acids  produces  in  it  also  a 
sudden  whiteness. 

This  colour  of  the  mucous  surfaces  acquires  a remark- 
able intensity  in  inflammation.  The  redness  becomes 
then  extremely  deep  on  account  of  the  quantity  of  blood 
that  is  accumulated  in  the  capillary  system.  It  is  par- 
ticularly in  dysentery  that  the  internal  surface  of  the 
intestines  exhibits  this  phenomenon  in  a striking  degree. 
I ought  however  to  observe  to  those  who  open  dead 
bodies,  that  they  never  should  lose  sight  of  the  original 
tinge  of  the  portion  of  the  mucous  system  they  examine, 
since  each  of  the  divisions  of  this  system  exhibits  in  its 
shades  remarkable  differences.  If  the  membrane  of  the 
bladder,  tbe  rectum,  &c.  is  found  as  red  as  that  of  the 
stomach  in  its  natural  state,  then  pronounce  that  there 
had  been  inflammation  ; if  the  redness  of  the  sinuses 


MUCOUS  SYSTEM. 


105 


equals  that  which  is  natural  to  the  bladder  and  the  rectum, 
decide  that  inflammation  had  existed  in  them.  There  is, 
as  I have  said,  a scale  of  colour  for  the  mucous  system. 
It  is  then  essential  to  have  an  accurate  knowledge  of  this 
scale,  a type  to  which  we  can  refer  the  inflammatory  state 
in  the  examination  of  dead  bodies,  ' 

Exhalants. 

Does  exhalation  take  place  upon  the  mucous  surfaces  ? 
The  analogy  of  the  skin  seems  to  indicate  it ; for  it  is 
well  proved  that  the  sweat  is  not  a transudation  through 
the  inorganic  pores  of  the  cutaneous  surface,  but  a real 
transmission  by  vessels  of  a peculiar  nature  and  continu- 
ous with  the  arterial  system. 

It  appears  at  first  that  the  pulmonary  perspiration 
which  takes  place  upon  the  mucous  surface  of  the  bron- 
chia, which  has  so  much  relation  with  that  of  the  skin, 
Avhich  increases  and  diminishes  according  as  this  dimin- 
ishes or  increases,  and  the  matter  of  which  is  probably  of 
the  same  nature ; it  appears,  I say,  that  the  pulmonary 
perspiration  is  made  at  least  in  great  part  by  the  system 
of  exhalant  vessels,  and  that  if  the  combination  of  the 
oxygen  of  the  air  with  the  hydrogen  of  the  blood  con- 
tributes to  produce  it,  during  the  act  of  respiration,  it  is 
but  in  very  small  quantity,  and  it  is  the  portion  that  is 
purely  aqueous.  Besides,  this  last  hypothesis  of  modern 
chemists,  contradictory  to  the  production  of  all  the  other 
fluids  thrown  out  by  the  mucous  surfaces,  appears  to  me 
ill  adapted  to  explain  the  formation  of  this.  When  the 
same  phenomenon  is  pi’oduced  in  many  places,  and  the 
explanation  that  is  given  of  it  is  applicable  only  to  one, 
we  should  be  suspicious  of  this  explanation. 

It  should  be  observed  in  regard  to  the  pulmonary  per- 
spiration, that  the  solution  of  the  mucous  fluid  which  lubri- 
cates the  bronchia,  in  the  air  constantly  inspired  and 
expired,  furnishes  a considerable  portion  of  this  vapour 
AmL.  III.  14 


106 


MUCOUS  SYSTEM. 


which,  insensible ^in  summer,  is  very  evident  in  winter, 
on  account  of  the  condensation  of  the  air.  The  mucous 
juices  are  dissolved  like  every  other  fluid  ; for  wherever 
there  is  atmospheric  air,  heat  and  moisture,  there  is  evapo- 
ration. Here  this  evaporation  is  even  a means  which 
nature  employs  to  rid  herself,  as  I have  said,  of  the  mu- 
cous juices.  If  they  are  too  abundant,  as  in  a cold,  then 
the  quantity  of  air  which  serves  as  a vehicle  to  them,  not 
increasing  in  proportion,  it  is  necessary  that  there"  should 
be  another  mode  of  evacuation ; this  is  expectoration 
which  compensates  for  what  the  air  cannot  remove  by 
solution. 

The  intestinal  juice  which  Haller  has  especially  con- 
sidered, but  which  appears  to  be  in  much  less  quantity 
than  he  thought  it,  the  oesophagean  and  gastric  juices, 
particularly  this  last  which  has  been  supposed  to  be  dis- 
tinct from  the  mucous  juices,  are  probably  deposited  by 
exhalation  upon  their  respective  mucous  surfaces.  But 
in  general  it  is  very  difficult  to  distinguish  with  precision 
w'hat  belongs  in  these  organs  to  the  exhalant  system,  from 
that  which  is  furnished  by  the  system  of  mucous  glands, 
which,  as  we  have  said,  are  everywhere  subjacent  to 
them.  Thus  we  constantly  see  the  mucous  fluids  of  the 
oesophagus,  the  stomach  and  the  intestines,  mixing  with 
the  oesophagean,  gastric  and  intestinal  fluids. 

As  on  the  one  hand  the  blood  vessels  ramify  almost 
naked  on  the  mucous  surfaces,  and  as  on  the  other  these 
vessels  are  always  the  origin  of  the  exhalants,  it  is  evi- 
dent, that  these  have  but  a short  course  to  run  to  arrive 
at  their  surfaces  ; they  are  rather,  pores  than  distinct  ves- 
sels. Hence  why  no  doubt  the  blood  has  so  great  a 
tendency  to  escape  by  the  exhalants  ; why  consequently 
hemorrhages  without  rupture  are  so  frequent  in  the  mu- 
cous system  ; why  this  afiection  can  be  classed  in  the 
diseases  of  this  system,  &c.  &c.  No  other,  by  the  arrange- 
ment of  the  arteries,  offers  to  the  exhalants  so  short  a 


MUCOUS  SYSTEM, 


107 


course  between  their  origin  and  termination.  Often  even, 
as  I have  said,  we  make  the  hlood  of  these  vessels  ooze 
in  the  dead  body  through  their  exhalants. 

Absorbents. 

The  absorption  of  the  mucous  membranes  is  evidently 
proved,  1st,  by  those  of  chyle  and  of  drinks  on  the  intes- 
tinal surfaces,  of  the  venereal  virus  upon  the  glans  penis 
and  the  canal  of  the  urethra,  of  the  variolous  when  the 
gums  are  rubbed  with  it,  of  the  serous  portion  of  the 
bile,  the  urine  and  the  semen,  when  they  remain  in  their 
respective  reservoirs.  2d,  When,  in  the  paralysis  of  the 
fleshy  fibres  that  terminate  the  rectum,  substances  are 
accumulated  at  the  extremity  of  this  intestine,  these  sub- 
stances often  become  hard,  an  efiect  probably  of  an  ab- 
sorption of  the  soft  parts.  3_d.  There  have  been  various 
cases  in  which  the  urine  has  been  almost  v/holly  absorbed 
by  the  mucous  surface  of  the  bladder,  where  there  have 
been  insurmountable  obstacles  in  the  urethra.  4th.  If  we 
respire,  by  means  of  a tube,  the  air  of  a large  vessel  filled 
with  the  exhalations  of  turpentine,  so  that  these  vapours 
can  only  act  upon  the  mucous  surface  of  the  bronchia, 
the  urine  has  the  peculiar  odour  that  always  arises  from 
the  use  of  this  substance,  the  exhalations  from  which  have 
been  introduced  into  the  blood  by  the  means  of  absorp- 
tion, &c. 

Whatever  may  be  the  mode  of  this  absorption,  it  ap- 
pears that  it  does  not  take  place  in  a constant  and  unin- 
terrupted manner,  like  those  of  the  serous  membranes,  in 
which  the  exhalant  and  absorbent  systems  are  in  a regular 
and  continual  alternation  of  action.  There  is  scarcely  any 
but  the  chylous  absorption,  that  of  drinks,  and  that  of 
the  aqueous  portion  of  the  secreted  fluids  remaining  in  a 
reservoir  as  they  come  from  their  glands,  that  constantly 
take  place.  Nothing  is  more  variable  than  the  other  ab- 
sorptions. Under  the  same  influence,  the  glans  takes  up 


108 


MUCOUS  SYSTEM. 


or  leaves  the  venereal  virus  ; the  internal  sui’face  of  the 
bronchia  sometimes  admits  and  sometimes  refuses  admit- 
tance to  contagious  miasmata.  There  are  more  cases  of 
retention  in  which  the  urine  is  not  absorbed  entirely, 
than  there  are  where  this  absorption  takes  place,  &c.  &c. 
The  innumerable  varieties  of  the  vital  forces  of  the  mu- 
cous membranes,  varieties  produced  by  those  of  the  stimuli 
with  Avhich  they  are  in  contact,  explain  these  phenomena. 
If  these  forces  are  raised  or  diminished  a little,  the  ab- 
sorption is  altered,  even  that  which  is  natural,  as  that  of 
the  chyle.  Take  a purgative  ; it  contracts,  shuts  even 
the  mouth  of  the  absorbents  of  the  intestinal  canal ; as 
long  as  the  irritation  continues,  all  the  drinks  that  are 
taken  pass  off  by  the  anus  ; at  the  end  of  four  or  five 
hours,  the  absorbents  gradually  recover  their  natural  tone 
and  absorption  recommences.  In  these  cases,  the  first 
discharges  are  only  the  intestinal  matters,  the  others  are 
the  copious  drinks  that  have  been  taken.  There  are  many 
diseases  in  which,  the  sensibility  of  the  chylous  absor- 
bents being  too  much  raised,  they  are  no  longer  in  relation 
with  the  aliments,  they  take  up  with  difficulty  the  resi- 
due of  them,  &c.  Deficiency  of  action  produces  the  same 
phenomenon  ; in  absorption  in  fact  it  is  a middle  degree 
of  sensibility  of  the  organ  which  produces  it,  a degree 
below  or  above  which  it  cannot  take  place. 

All  the  mucous  absorbents  appear  to  go  to  the  thoracic 
duct. 


Nerves. 

I would  remark  that  at  all  the  origins  of  the  mucous  sys- 
tem, where  the  animal  sensibility  is  very  great  and  where 
it  places  us,  like  the  skin,  in  relation  with  external  bodies, 
cerebral  nerves  are  distributed.  The  pituitary  and  pala- 
tine membranes,  the  conjunctiva,  the  mucous  surface  of 
the  rectum,  the  glans  penis,  the  prepuce,  &c.  exhibit 
this  fact  very  evidently.  There  are  hardly  any  nervous 


MUCOUS  SYSTEM, 


109 


filaments  coming  from  the  ganglions  in  these  diflferentj 
places. 

On  the  contrary,  this  last  species  of  nerves  is  the  pre- 
dominant one  in  the  intestines,  in  all  the  excretories,  in 
the  reservoirs  of  the  secreted  fluids,  &c,  places  where  the 
organic  sensibility  is  the  most  evident. 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  MHCOtTS  SYSTEM. 

I.  Properties  of  Texture. 

Extensibility  and  contractility  are  much  less  in  this 
system  than  they  at  first  appear  to  be,  on  account  of  the 
numerous  folds  which  it  exhibits  in  the  hollow  organs 
during  their  contraction,  folds  which  are  developed  only 
during  extension,  as  we  have  seen.  Yet  these  two  pro- 
perties become  very  evident  in  some  cases.  The  excre- 
tories are  capable  of  taking  a size  much  larger  than  is 
natural  to  them.  This  is  seen  in  the  ureters  in  particu- 
lar, which  are  sometimes  found  as  large  as  an  intestine. 
The  ductus  choledochus  and  the  pancreatic  duct  have 
often  also  these  dilatations.  The  urethra  and  the  salivary 
ducts  appear  to  be  less  extensible  than  the  others.  If 
they  have  ever  so  little  obstacles  from  strictures,  con- 
tractions, &c.  they  break  rather  than  stretch  ; hence  vari- 
ous urinary  and  salivary  fistulas. 

Hence  there  is,  as  we  see,  many  varieties  in  the  degrees 
of  the  extensibility  of  the  mucous  system ; it  is  the  same 
with  regard  to  the  contractility  of  texture.  These  two 


110 


MUCOUS  SYSTEM. 


properties  are  besides  capable  of  being  put  rapidly  int® 
action.  We  know  that  the  stomach,  the  intestines,  the 
bladder,  &c.  pass  in  an  instant  from  a great  size  to  ex- 
treme contraction.  Their  functions  even  suppose  this 
rapidity,  without  which  they  could  not  be  performed. 
The  palatine  membrane  which  lines  the  cheeks,  exhibits 
the  same  phenomenon  when  the  mouth  is  filled  with  air, 
aliments,  &c.  which  are  afterwards  expelled  from  it. 

W”hen  the  usual  fluids  cease  to  pass  through  the  mucous 
ducts,  they  remain  in  permanent  contraction  ; this  is  what 
takes  place  in  the  intestines  below  a preternatural  anus. 
I have  seen  in  this  case  the  csecum  and  the  rectum  re- 
duced to  the  size  of  a large  quill.  Yet  there  is  never  then 
an  obliteration  of  their  parietes,  on  account  of  the  presence 
of  the  mucous  juices,  of  which  the  patient  always  passes 
a certain  quantity.  The  urethra,  after  the  operations  for 
stone  in  which  the  urine  passes  for  a long  time  through 
the  wound,  and  in  the  great  fistulas  in  the  perineum  or 
above  the  pubis,  the  salivary  ducts  in  wounds  which  affect 
them  and  through  which  the  whole  saliva  is  discharged, 
the  nasal  canal  in  fistulas  lachrymales,  contract  also  more 
or  less,  but  are  never  obliterated.  We  know  that  the  vas 
deferens  is  often  a very  long  time  without  having  semen 
pass  through  it,  and  yet  it  remains  open.  Tliis  phenome- 
non distinguishes  the  mucous  ducts  from  the  arterial, 
Avhich,  when  the  course  of  blood  is  interrupted  in  them, 
change  into  ligaments  in  which  every  thing  like  a canal 
disappears.  We  ought  not  to  lose  sight  of  this  phenome- 
non of  all  the  mucous  ducts ; it  proves  the  incorrectness 
of  the  practice  of  those  who,  thinking  that  at  the  end  of 
some  time  it  is  impossible  tq  re-establish,  in  fistulas,  the 
natural  way,  think  it  necessary  to  make  an  artificial  one. 

The  mucous  tubes  are  not  only  not  obliterated  when 
they  are  empty,  but  when  inflamed  they  do  not  even  con- 
tract adhesions  of  their  parietes,  as  so  often  happens  in 
the  serous  cavities,  in  ihe  cellular  texture,  &c.  Observe 

t 


MUCOUS  SYSTEM. 


Ill 


how  important  this  fact  is  to  the  great  functions  of  life  ; 
what  would  indeed  become  of  these  functions,  if  iii 
catarrhs  of  the  intestines,  the  bladder,  the  stomach,  the 
oesophagus,  the  excretories,  &c.  these  adhesions  were  as 
frequent  as  they  are  in  pleurisy,  peritonitis,  pericarditis, 
&c. 

I 

II.  Vital  Properties. 

Few  systems  live  in  a more  active  manner  than  this 
few  exhibit  the  vital  forces  in  a higher  degree-. 

Properties  of  x8.nimal  Life. 

Constantly  in  relation,  like  the  integuments,  with  ex- 
ternal' bodies,  the  mucous  surfaces  have  occasion  for  a 
sensibility  which  would  enable  the  mind  to  perceive  these 
relations,  especially  at  the  origin  of  these  surfaces.  Thus 
the  animal  sensibility  is  very  much  developed  there.  It  is 
even  superior  in  it  in  many  places  to  that  of  the  cutaneous 
organ,  in  which  no  sensation  is  as  acute  as  those  which 
take  place  on  the  pituitary  membrane  from  odours,  upon 
the  palatine  from  tastes,  upon  the  surface  of  the  vagina, 
the  urethra,  the  glans  penis  during  coition.  But  without 
speaking  of  these  exaggerations  of  sensibility,  if  I may  so 
express  myself,  all  the  natural  phenomena  of  the  mucous 
surfaces  prove  this  property  in  an  evident  manner  ; it  is 
unnecessary  however  to  pause  for  these  phenomena. 

I would  only  observe  that  this  sensibility,  like  that  of 
the  cutaneous  organ,  is  essentially  subjected  to  the  power- 
ful influence  of  habit,  which  tending  constantly  to  blunt 
the  acuteness  of  the  sensation  of  which  they  are  the  seat, 
brings  equally  to  indifierence  the  pain  and  the  pleasure 
they  make  us  experience,  and  of  which  it  is  the  medium, 
as  we  know.  1st.  I say  that  habit  brings  to  indiflference 
the  painful  sensations  arising  upon  the  mucous  membranes. 
The  presence  of  a sound  in  the  urethra  for  the  first  time, 


113 


MUCOUS  SYSTEM. 


is  distressing  the  first  day,  painful  the  second,  incon' 
venient  the  third,  and  insensible  the  fourth.  Pessaries 
introduced  into  the  vagina,  bougies  into  the  rectum,  tents 
fixed  in  the  nasal  fossae,  and  a canula  kept  for  a length 
of  time  in  the  nasal  canal,  exhibit  in  different  degrees  the 
same  phenomena.  It  is  upon  this  remark  that  is  founded 
the  possibility  of  the  introduction  of  sounds  into  the  wind- 
pipe to  aid  respiration,  and  into  the  oesophagus  to  pro- 
duce an  artificial  deglutition.  This  law  of  habit  can  even 
transform  into  a pleasure  an  impression  at  first  painful ; 
the  use  of  snuff  for  the  pituitary  membrane  and  differ- 
ent aliments  for  the  palatine,  furnish  well  known  ex- 
amples of  this.  2d.  I say  that  habit  brings  to  indiffer- 
ence agreeable  sensations  arising  on  the  mucous  surfaces  ; 
the  perfumer,  placed  in  an  odoriferous  atmosphere,  the 
cook,  whose  palate  is  constantly  affected  by  delicious 
tastes,  do  not  find  in  their  professions  the  acute  enjoy- 
ments they  give  to  others.  From  habit  can  even  arise 
the  succession  from  pleasure  to  painful  sensations,  as  in 
the  preceding  case  it  converts  pain  to  pleasure. 

I would  however  observe  that  this  remarkable  influence 
of  habit  is  only  exerted  upon  sensations  produced  by 
simple  contact,  and  not  upon  those  produced  by  real  in- 
juries, as  the  tearing,  the  forced  stretching,  the  cutting  or 
pinching  of  the  mucous  system  ; thus  it  does  not  miti- 
gate the  pains  caused  in  the  bladder  by  pressure  and  by 
the  tearing  a stone  occasions,  or  on  the  surface  of  the 
womb,  of  the  nasal  fossae,  &c.  by  a polypus,  on  that  of 
the  oesophagus  or  the  wind-pipe  by  a sharp  and  uneven 
body  accidentally  lodged  there,  &c.  &c. 

It  is  to  this  power  of  habit  over  the  sensibility  of  the 
mucous  system,  that  must  be  in  part  referred  the  gradual 
diminution  of  its  functions,  which  accompanies  age. 
Every  thing  is  siimulant  in  infancy,  every  thing  is  blunt- 
ed in  old  age.  In  one,  the  very  active  sensibility  of  the 
alimentary,  biliary,  urinary,  salivai’y  surfaces,  &c.  con- 


MUCOUS  SYSTEM. 


113 


tributes  principally  to  produce  that  rapidity  with  which 
the  digestive  and  secretory  phenomena  succeed  each 
other ; in  the  other,  this  sensibility  blunted  by  habitual 
contact,  connects  but  slowly  the  same  phenomena. 

Is  it  not  from  the  same  cause  that  arises  this  remark- 
able modification  of  the  sensibility  of  this  system,  viz. 
that  at  its  origins,  as  upon  the  pituitary,  the  palatine  mem- 
branes, the  (Esophagus,  the  glans  penis,  the  opening  of 
the  rectum,  &c.  it  gives  us  the  sensation  of  the  bodies 
with  which  it  is  in  contact,  and  that  it  does  not  give 
this  sensation  in  the  very  deep  organs  which  it  lines, 
as  in  the  intestines,  the  excretories,  the  gall-bladder, 
&c.  ? In  the  interior  of  the  organs,  this  contact  is  always 
uniform  ; the  bladder  only-  knows  the  contact  of  the  urine, 
the  gall-bladder  that  of  the  bile,  the  stomach  that  of  the 
aliments  masticated  and  reduced,  whatever  may  be  their 
diversity,  to  an  uniform,  pulpy  mass.  This  uniformity 
of  sensation  produces  no  perception,  because  in  order  to 
perceive,  it  is  necessary  to  compare,  and  here  the  two 
terms  of  comparison  are  wanting.  Thus  the  fcetus  has 
no  sensation  of  the  waters  of  the  amnios ; thus,  the  air, 
very  irritating  to  a new  born  infant,  becomes  insensible 
to  it.  On  the  contrary,  at  the  beginning  of  the  mucous 
membranes,  the  stimulants  vary  every  instant ; the  mind 
can  then  perceive  the  presence  of  them,  because  it  can 
establish  approximations  between  their  different  modes  of 
action.  What  I say  is  so  true,  that  if  in  the  interior  of 
the  organs,  the  mucous  membranes  are  in  contact  with  a 
foreign  body,  different  from  that  which  they  are  accus- 
tomed to,  they  transmit  the  sensation  of  it  to  the  mind. 
A catheter  in  the  bladder,  sounds  introduced  into  the 
stomach,  &c.  are  examples  of  this.  Fresh  air,  in  great  heat 
of  the  atmosphere,  suddenly  introduced  into  the  trachea, 
carries  an  agreeable  sensation  ovei^ie  whole  surface  of 
the  bronchia;  but  habit  soon  renders  us  insensible  to  it 
15 


VOL.  III. 


114 


MUCOUS  SYSTEM. 


and  we  cease  to  have  the  perception  of  it.  Yet  it  is  to 
be  observed  that  when  the  intestines  come  out  in  pre- 
ternatural inversions  of  the  anus,  their  sensibility  nevei^ 
becomes  so  acute  as  that  of  the  palatine,  pituitary  sur- 
faces, &c.  &c.  The  absence  of  cerebral  nerves  no  doubt 
has  an  influence  upon  this  phenomenon. 

The  sensibility  of  the  mucous  system  is  much  raised 
in  inflammations ; acute  catarrhs  are,  as  we  know,  very 
painful.  The  contact  of  bodies  is  then  not  only  felt,  but 
is  very  disagreeable.  I would  observe  however  that  the 
sensibility  never  rises  so  high  as  it  does  in  the  inflamed 
cellular,  serous,  fibrous  systems,  &c.  ' A phlegmon,  a 
pleurisy,  &c.  compared  with  a catarrh,  are  sufficient  to 
convince  us  of  this.  We  may  say  that  the  organs  least 
accustomed  to  feel  in  the  natural  state,  experience  in  dis- 
eases the  most  acute  sensations. 

There  is  no  animal  contractility  in  the  mucous  system. 

Properties  of  Organic  Life. 

Organic  sensibility  and  insensible  contractility  are  very 
evident  in  the  mucous  system.  They  are  constantly  put  in 
action  in  it  by  four  different  causes  ; 1st,  by  the  nutrition 
of  this  system ; 2d,  by  the  absorption  that  takes  place  in 
it,  either  naturally  or  accidentally  ; 3d,  by  its  exhalation  ; 
4th,  by  the  constant  secretion  of  its  glands.  These  two 
properties  are  the  original  causes  of  all  these  functions, 
the  increase  and  diminution  of  which  are  truly  the  indices 
of  the  state  of  these  glands.  As  a thousand  causes  con- 
tinually act  upon  the  mucous  surfaces,  as  a thousand  dif- 
ferent stimuli  continually  excite  them,  especially  at  their 
origin,  this  state  is  incessantly  varying  like  the  functions 
that  result  from  it. 

The  mucous  system  differs  then  from  most  of  the 
others ; 1st,  in  this,  that  the  organic  sensibility  and  the 
insensible  contractility  are  habitually  more  exalted  in  it. 


MUCOUS  SYSTEM. 


115 


on  account  of  the  more  numerous  functions  over  which 
they  preside ; 2d,  in  this,  that  they  incessantly  vary,  on 
account  of  the  variety  of  the  stimuli.  Observe  in  fact 
that,  in  the  osseous,  fibrous,  cartilaginous,  muscular,  ner- 
vous systems,  &c.  on  the  one  hand,  these  properties  are  put 
in  action  only  by  nutrition  ; and  on  the  other,  no  stimu- 
lant being  in  contact  with  these  systems,  they  always  re- 
main at  the  same  degree. 

Hence  it  is  not  astonishing  that  the  diseases  which  espe- 
cially put  in  action  the  organic  sensibility  and  the  insensi- 
ble contractility  of  the  same  species,  should  be  so  frequent 
in  the  mucous  organs.  All  the  catarrhal  affections,  both 
acute  and  chronic,  all  the  hemorrhages,  various  and 
numerous  tumours,  polypi,  fungi,  &c.  all  kinds  of  excoria- 
tions, ulcers,  &c.  of  which  they  are  the  seat,  are  derived 
from  the  various  alterations  of  which  their  organic  pro- 
perties are  susceptible. 

It  is  also  to  these  alterations  that  milst  be  attributed  a 
remarkable  phenomenon,  viz.  the  innumerable  varieties 
the  mucous  fluids  exhibit  in  diseases.  Take  for  example 
those  that  are  thrown  off  from  the  internal  surface  of  the 
bronchia,  those  that  are  brought  up  by  expectoration,  and 
which  we  can  examine  better  than  others,  because  they 
are  mixed  with  no  foreign  substance  ; observe  how  they 
differ,  in  the  different  affections  of  the  chest : sometimes 
they  have  a yellowish  and  as  it  were  bilious  tinge  ; some- 
times they  are  frothy  in  the  vessel  which  receives  them  ; 
sometimes  they  adhere  to  it  with  tenacity,  and  at  others 
they  are  easily  detached  from  it.  Viscid  or  liquid,  fetid 
or  without  odour,  grey,  white,  green  or  even  black  in  the 
morning,  they  have  a thousand  external  appearances  which 
evidently  denote  differences  in  their  composition,  differ- 
ences which  chemists  have  not  yet  explained  to  us.  I 
do  not  speak  of  the  cases  where  as  in  phthisis,  hemopty- 
sis, &c.  foreign  substances  are  mixed  with  these  mucous 
juices.  Now  it  is  evident  that  all  these  varieties  depend 


116 


MUCOUS  SYSTEM 


only  upon  the  varieties  of  the  organic  sensibility  of  the 
bronchial  glands  or  of  the  membrane  upon  which  they 
pour  out  their  fluids.  According  as  the  property  is  dif- 
ferently altered  in  the  mucous  system,  it  is  in  relation 
with  difierent  substances,  admits  some  and  rejects  others. 
The  same  organ,  the  same  vessels  can  there,  according  to 
the  state  of  the  forces  that  animate  them,  separate  from 
the  mass  of  blood  many  different  substances,  rejecting 
one  to-day  and  admitting  it  to-morrow,  &c. 

Do  you  wish  for  other  proofs  of  the  innumerable  varie- 
ties which  the  different  modifications  of  the  organic  sen- 
sibility of  the  mucous  membranes  produce  in  their  func- 
tions ? Observe  the  urethra ; in  the  ordinary  state  it  lets 
the  urine  pass  freely  ; in  the  excitement  in  which  its 
forces  are  in  erection,  its  sensibility  repels  it  and  admits 
only  the  semen.  Who  does  not  know  that  in  one  species 
of  epiphora,  the  mucous  passages  for  the  tears  are  open, 
and  that  the  diminution  only  of  their  vital  forces  prevents 
this  fluid  from  flowing  in  them  ? The  sensibility  of  the 
mucous  surfaces  is  oftentimes  so  altered  that  their  glands 
refuse  to  admit  every  kind  of  fluid  ; this  happens  in  the 
beginning  of  some  peripneumonies,  in  which  expectora- 
tion is  entirely  suppressed,  it  is  always  a serious  begin- 
ning, and  even  an  indication  of  death,  if  the  state  of  the 
sensibility  does  not  change,  unless  a relaxation,  as  it  is 
commonly  called,  takes  place. 

In  general,  I think  that  there  are  but  few  systems' 
which  deserve,  more  than  this  of  which  we  are  treating, 
to  fix  the  attention  of  physicians,  on  account  of  the  in- 
numerable alterations  of  which  it  is  susceptible,  altera- 
tions which  almost  always  suppose  those  of  the  predomi- 
nant vital  properties  of  this  system,  as  the  alterations  of 
the  muscular,  nervous  systems,  &c.  most  often  put  in  ac- 
tion the  properties  which  more  particularly  belong  to 
them,  viz.  animal  contractility  for  one,  and  the  sensibility 
of  the  same  species  for  the  other. 


MUCOUS  SYSTEM. 


117 


The  sensible  organiu  contractility  does  not  appear  to  be 
the  attribute  of  the  mucous  system  ; yet  there  is  often  in 
it  something  more  than  the  insensible  oscillations  which 
compose  the  other  organic  contractility.  For  example,  in 
the  emission  of  semen,  in  which  there  is  no  agent  of  im- 
pulse at  the  extremity  of  the  urethra,  as  in  the  evacuation 
of  urine,  it  is  very  probable  that  this  is  spasmodically 
contracted  to  produce  the  jet,  oftentimes  very  strong, 
which  then  takes  place.  The  following  phenomenon 
which  I have  observed  in  myself  appears  to  belong  to  the 
same  cause.  In  gaping,  there  sometimes  escapes  from  the 
mouth  then  wide  open,  a small  jet  of  fluid,  which  coming 
from  the  lateral  parts  of  this  cavity  that  it  passes  over,  is 
thrown  at  some  distance ; if  a surface  is  then  before  the 
mouth,  as  when  we  read  a book,  this  fluid  is  spread  in 
small  drops  upon  this  surface  ; it  is  the  saliva  which  the 
excretorj'-  duct  of  Steno  throws  out  with  force.  Now  on 
the  one  hand  this  duct  is  almost  wholly  mucous,  and  on 
the  other  it  has  not  at  its  posterior  part  a muscular  agent 
of  impulse.  Perhaps  the  excretories  which  pour  out  their 
fluids  in  the  deep  parts  of  the  organs,  exhibit  the  same 
phenomenon.  We  know  that  the  milk  is  also  sometimes 
subject  to  a kind  of  ejection,  when  it  is  very  abundant, 
an  ejection  which  supposes  a powerful  contraction  of  the 
lactiferous  ducts.  In  general,  these  different  motions 
analogous  to  that  of  the  dai'tos,  of  the  cellular  texture, 
'&c.  appear  to  hold  a middle  place  between  those  of  tone 
and  those  of  irritability. 

Sympathies. 

There  are  few  systems  that  sympathize  more  frequently 
with  the  others  than  this.  Now  in  its  sympathies,  it 
sometimes  influences  and  sometimes  is  influenced.  The 
first  Tissot  calls  the  active  mode  of  sympathy,  the  second 
the  passive.  Let  us  make  use  of  this  classification. 


ns 


MUCOUS  SYSTEM. 


Active  Sympathies. 

One  point  of  the  mucous  system  being  inflamed,  irri- 
tated or  stimulated  in  any  way,  all  the  vital  forces  can 
enter  separately  into  action  in  the  other  systems. 

Sometimes  it  is  the  animal  contractility  that  is  brought 
sympathetically  into  action  ; thus  the  diaphragm,  the  in- 
tercostal and  abdominal  muscles  contract  to  produce  sneez- 
ing from  irritation  of  the  pituitary  membrane,  or  cough 
from  the  irritation  of  the  membrane  of  the  bronchia,  or 
from  that  even  of  the  surface  of  the  stomach,  which  pro- 
duces stomachic  coughs,  which,  as  we  know,  have  nothing 
to  do  with  affections  of  the  chest.  We  know  the  general 
spasm  that  seizes  all  the  muscles  the  instant  a foreign 
body  passes  between  the  mucous  edges  of  the  epiglottis. 
Stones  of  the  bladder  and  the  urethra,  by  making  the 
cremaster  contract  sympathetically,  produce  retraction  of 
the  testicle.  Physicians  might,  I think,  profit  by  the 
knowledge  of  these  mucous  sympathies.  In  apoplexy, 
in  which  the  bronchia  is  sometimes  filled  with  mucus 
that  the  patient  cannot  evacuate,  the  action  of  ammonia 
upon  the  pituitary  membrane  produces  the  double  eflfect, 
1st,  of  stimulating  the  brain  as  blisters  do  ; 2d,  of  free- 
ing, by  the  cough  it  occasions,  the  surface  of  the  bron- 
chia, which  being  obstructed,  is  an  obstacle  to  the  passage 
of  the  air. 

Sometimes  it  is  the  animal  sensibility  that  is  put  into 
action  by  an  affection  of  the  mucous  surfaces.  The  stone, 
that  irritates  that  of  the  bladder,  causes  an  itching  at  the 
end  of  the  glans  penis.  That  of  the  intestines  being  irri- 
tated by  worms,  an  inconvenient  itching  is  felt  at  the  end 
of  the  nose.  Whytt  has  seen  a foreign  body  introduced 
into  the  ear,  affect  painfully  the  whole  corresponding  side 
of  the  head  ; an  ulcer  of  the  bladder,  produce  every  time 
the  patient  passed  water,  a pain  on  the  superior  part  of 
the  thigh,  &c.  &c. 


MUCOUS  SYSTEM. 


119 


The  sensible  organic  contractility  is  often  sympatheti- 
cally excited  by  the  affections  of  the  mucous  system.  I 
might  at  first  refer  to  this  subject  what  I have  observed 
respecting  the  organic  muscles,  almost  all  of  which  move 
from  an  excitement  of  a contiguous  mucous  surface ; but 
that  is  a natural  phenomenon  ; there  are  many  others  that 
are  preternatural.  A stone  that  irritates  the  internal  sur- 
face of  the  pelvis  of  the  kidney  produces  vomiting,  which 
is,  as  we  know,  produced  any  time  at  will  by  an  irrita- 
tion of  the  uvula.  The  instant  the  semen  passes  the 
urethra  in  coition,  the  action  of  the  heart  is  commonly 
accelerated.  Tissot  speaks  of  a stone  which,  being  en- 
tangled in  the  duct  of  Warton,  produced  a sympathetic 
discharge  from  the  bowels.  I saw  a't  the  Hotel  Dieu  two 
women,  who,  whenever  they  menstruated,  and  the  mucous 
surface  of  the  womb  was  consequently  in  activity,  could 
retain  the  urine  but  a short  time  in  the  bladder,  which 
contracted  involuntarily  to  expel  it  the  moment  it  enter 
ed  it.  At  ordinary  times,  there  was  nothing  peculiar  in 
the  evacuation  of  this  fluid. 

As  to  the  sympathies  of  insensible  contractility  and  of 
organic  sensibility,  they  take  place  when  a mucous  sur- 
face being  irritated  towards  the  extremity  of  an  excretory 
duct,  the  gland  of  this  duct  is  brought  into  action,  when, 
for  example,  the  saliva  flows  in  greater  abundance  by  the 
action  of  sialagogues  upon  the  extremity  of  the  Stenonian 
duct.  Whenever  there  is  a gastric  derangement  and  the 
mucous  surface  of  the  stomach  consequently  suffers,  the 
surface  of  the  tongue  is  sympathetically  affected  ; the 
glands  situated  under  this  surface  increase  their  action 
and  hence  that  white  mucous  coat,  that  is  commonly  call- 
ed a foul  tongue,  which  is  a real  sympathetic  catarrh,  but 
which  can  however  exist  idiopathically.  Here  also  is  to 
be  referred  the  remarkable  influence  of  the  mucous  sys- 
tem upon  the  cutaneous ; thus  during  digestion,  in  which 
the  mucous  juices  pour  out  abundantly  from  all  sides  into 


120 


MUCOUS  SYSTEM. 


the  stomach  and  the  intestines,  and  in  which  the  mucous 
membranes  of  the  gastric  viscera  are  consequently  in 
great  action,  the  fluid  of  insensible  transpiration  is  lessen- 
ed remarkably,  according  to  the  observation  of  Sanctorius ; 
it  is  in  very  small  quantity  three  hours  after  the  meal,  so 
that  the  action  of  the  cutaneous  organ  is  evidently  less 
energetic.  Thus  during  sleep,  in  which  all  the  internal 
functions  become  more  evident  and  are  exerted  to  their 
utmost,  and  in  which  the  sensibility  of  the  mucous  mem- 
branes is  consequently  strongly  developed,  the  skin  seems 
to  be  struck  with  a species  of  atony  ; it  becomes  cold 
more  easily,  it  allows  less  substances  to  escape  from  it, 
&c.  To  these  sympathies  also  can  be  referred  many  phe- 
nomena of  hemorrhages.  We  know  with  what  facility 
the  mucous  surface  ceasing,  from  any  accidental  cause,  to 
throw  out  blood,  as  happens  so  often  on  that  of  the  womb, 
another  is  immediately  affected  and  discharges  this  fluid  ; 
hence  hemorrhages  from  the  nose,  the  stomach,  the  chest, 
' &c.  from  the  suppression  of  those  of  the  uterus,  &c. 

Passive  Sympathies, 

In  many  cases,  the  other  systems  being  irritated,  the 
animal  sensibility  of  this  is  brought  into  action.  Among 
the  numerous  examples  of  this  fact,  the  following  is  a re- 
markable one.  In  many  diseases  in  which  organs  foreign 
to  the  mucous  system  are  affected,  we  experience  a sensa- 
tion of  burning  heat  in  the  mouth,  the  stomach,  the  in- 
testines, &c.  and  yet  the  mucous  surface,  the  seat  of  this 
sensation,  does  not  disengage  more  caloric  than  usual ; 
we  may  be  convinced  of  this  by  placing  the  fingers  in 
the  mouth.  This  sensation  is  of  the  same  nature  as  that 
which  we  refer  to  the  glans  penis  when  there  is  a stone 
in  the  bladder,  as  that  which  is  experienced  at  the  end  of 
the  nose  from  worms  in  the  intestines,  &c.  There  is  no 
material  cause  of  pain,  and  yet  there  is  suffering.  Thus 
in  intermittent  fevers  we  experience  a cutaneous  shiver- 


MUCOUS  SYSTEM. 


121 


ing,  though  the  skin  may  be  as  warm  as  usual  ; I would 
observe  in  respect  to  this,  that  the  mucous  membranes  are 
hardly  ever  the  seat  of  an  analogous  sensation  of  sympa- 
thetic cold,  but  it  is  almost  always  a sensation  of  heat 
that  the  aberrations  of  the  vital  forces  produce  in  them. 
Whence  arises  this  difference  between  them  and  the 
cutaneous  organs  ? I know  not.  I attribute  also  to  a 
sympathy  of  animal  sensibility  the  great  thirst  which 
takes  place  in  all  the  severe  affections  of  any  part.  In 
all  great  wounds,  after  severe  operations,  in  experiments 
on  living  animals,  &c.  we  observe  this  thirst  which  de- 
pends upon  a sympathetic  affection  of  the  whole  mucous 
surface  that  extends  into  the  mouth,  the  stomach  and  the 
oesophagus. 

Animal  contractility  cannot  be  put  sympathetically 
into  action  in  the  mucous  system,  since  it  does  not  exist 
in  it. 

The  same  is  true  of  the  sensible  organic  contractility. 
It  is  possible  that  sometimes  the  kind  of  motion  we  have 
noticed,  and  which  resembles  this  property,  may  be  sym- 
pathetically excited ; I know  no  example  of  it. 

The  insensible  organic  contractility  is  here  very  fre- 
quently in  sympathetic  activity.  It  is  the  skin  especially 
which  exercises  by  means  of  this  property,  a great  influ- 
ence upon  the  mucous  system.  1st.  In  hemorrhages  of 
the  mucous  surface  of  the  womb,  the  nostrils,  &c.  a cold 
body  applied  to  the  skin  in  the  neighbourhood,  contracts 
this  surface  and  stops  the  blood.  2d.  Who  does  not 
know  that  the  production  of  most  catarrhs  is  often  the 
sudden  consequence  of  the  action  of  cold  on  the  cutane- 
ous organ  ? 3d.  In  various  affections  of  the  mucous 

membranes,  baths  which  relax  and  expand  the  skin,  fre- 
quently produce  happy  effects.  4th.  When  the  tempera- 
ture of  the  atmosphere  benumbs  the  cutaneous  tone,  that 
of  the  mucous  system  receives  a remarkable  increase  of 

VOL.  III.  16 


122 


MUCOUS  SYSTEM. 


energy.  Hence  why  in  winter  and  in  cold  climates,  in 
which  the  functions  of  the  skin  are  very  much  diminish- 
ed, all  those  of  this  system  increase  in  proportion.  Hence 
the  more  evident  pulmonary  exhalation,  the  more  abun- 
dant internal  secretions,  a more  active  digestion,  more 
quickly  performed  and  consequently  an  appetite  more 
easily  excited.  5th.  When  on  the  contrary  the  heat  of 
the  climate  and  the  season  relax  and  expand  the  cutane- 
ous surface,  the  mucous  surface  is  in  proportion  contract- 
ed ; in  summer,  at  noon,  &c,  there  is  a diminution  of  the 
secretions,  of  that  of  the  urine  especially,  a slowness  in 
the  digestive  phenomena  from  a defect  in  the  action  of 
the  stomach  and  intestines,  an  appetite  slow  to  return, 
&c.  6th.  In  various  general  affections  of  the  skin,  cer- 
tain portions  of  the  mucous  membranes  are  almost  alwa}'^s 
affected.  In  scarlet  fever,  the  throat  most  usually  suffers 
sympathetically.  This  phenomenon  is  very  common  in 
small  pox.  7th.  In  the  latter  periods  of  organic  affections 
of  the  viscera,  as  in  phthisis,  diseases  of  the  heart,  en- 
largements of  the  liver,  cancers  of  the  womb,  &c.  the 
mucous  membranes  are  affected  like  the  serous  surfaces. 
The  kind  of  atony  in  which  they  then  are,  produces  a 
more  copious  flow  of  mucous  juices  in  them  which  are 
altered,  become  more  fluid,  &c.  ; hence  the  diarrhoeas 
that  are  called  colliquative,  which  are  then  to  the  mucous 
surfaces,  what  dropsies  are  to  the  serous  ones;  8th.  It  is 
also  to  this  atony  that  must  be  attributed  the  pectoral 
hemorrhages  which  so  frequently  take  place  in  the  last 
periods  of  organic  diseases,  in  those  of  the  heart  espe- 
cially. During  the  short  time  that  I have  been  at  the 
Hotel  Dieu,  there  has  already  died  more  than  twenty 
patients  whom  I have  opened,  of  these  affections  almost 
forgotten  by  all  practitioners  before  the  time  of  Corvi- 
sart ; I have  only  observed  four  examples  in  which 
passive  hemorrhage  of  the  lungs  was  not  the  precursor  of 
death. 


MUCOUS  SYSTEM. 


123 


Character  of  the  Vital  Properties. 

From  what  we  have  thus  far  said,  it  is  evident  that  the 
mucous  system  is  one  of  those  of  the  whole  economy,  in 
which  life  is  the  most  active.  Always  in  contact  with 
substances  that  stimulate  and  irritate  it,  it  is  as  it  were 
like  the  skin,  in  continual  action.  Yet  the  life  is  not  the 
same  in  all  its  parts  ; it  undergoes  in  each  remarkable 
modifications,  which  no  doubt  depend  on  those  we  have 
pointed  out  in  the  organization  of  this  system,  in  the 
nature  of  its  corion,  in  the  arrangement  of  its  papillae,  in 
the  distribution  of  its  vessels  and  its  nerves,  in  that  of 
its  glands,  &c. ; for  as  we  have  seen,  none  of  these  essen- 
tial bases  of  the  mucous  system  is  everywhere  arranged 
in  the  same  manner.  There  is  an  organization  common 
to  the  system,  and  one  peculiar  to  each  of  its  divisions. 
It  is  the  same  in  regard  to  its  life  ; there  is  a life  com- 
mon to  the  system,  and  as  many  peculiar  ones  as  there 
are  parts  to  which  it  is  extended.  We  know  how  much 
the  animal  sensibility  of  the  pituitary  membrane  differs 
from  that  of  the  palatine,  how  powerfully  the  membrane 
of  the  glans  penis  and  the  urethra  is  stimulated  by  the 
passage  of  the  semen  which  makes  no  impression  upon 
any  other  mucous  surface.  The  same  is  true  in  regard  to 
the  organic  sensibility  and  the  contractility  of  the  same 
species.  Each  mucous  surface,  in  relation  with  the  fluid 
it  is  accustomed  to,  would  bear  the  others  with  difficulty. 
The  urine  would  be  a stimulant  for  the  stomach  and  tlie 
gastric  juice  for  the  bladder ; the  bile  that  remains  in  the 
gall-bladder  would  produce  a catarrh  upon  the  membrane 
of  the  nose,  in  the  vesiculse  seminales,  &c. 

From  these  varieties  in  the  vital  forces  of  each  division 
of  the  mucous  system,  it  is  not  astonishing  that  the  dis- 
eases of  this  system  should  also  be  very  variable.  Each 
has  a general  character,  but  this  is  modified  in  each  mu- 
cous surface.  There  is  an  order  of  symptoms  common 


124 


MUCOUS  SYSTCM. 


to  all  catarrhs ; but  each  has  its  peculiar  signs,  each  has 
its  different  products.  The  fluid  from  a pulmonary 
catarrh  does  not  resemble  that  from  a nasal  one  ; that 
coming  from  a urethral,  vesical  catarrh,  &c.  is  wholly  dif- 
ferent from  that  from  an  intestinal  one.  These  fluids 
exhibit  in  their  morbid  changes  the  same  differences  that 
we  have  pointed  out  in  their  natural  composition,  differ- 
ences which  are  derived  like  them,  from  the  different 
vitality  of  each  portion  of  the  mucous  system. 

It  is  to  those  varieties  of  life  and  the  vital  forces  that 
must  be  referred  also  those  of  the  sympathies.  Each 
portion  of  this  system  has  a peculiar  sympathetic  action 
upon  the  other  organs.  The  pituitary  alone  being  irri- 
tated produces  sneezing.  You  would  excite  in  vain  the 
extremity  of  the  glans  penis,  the  rectum,  &c.  you  would 
never  produce  vomiting  as  you  do  by  stimulating  the 
uvula. 

An  important  remark  should  here  be  made  in  regard 
to  the  stomach.  We  know  that  there  is  no  organ  which 
performs  a more  important  part  in  the  sympathies  than 
this.  The  least  aflection  of  this  important  viscus,  the 
least  gastric  derangement,  spread  over  the  whole  animal 
economy  a painful  influence ; all  the  other  parts  feel  it. 
I do  not  believe  even  that  there  is  any  uneasiness  more 
fatiguing  and  general  than  that  which  we  then  experience 
in  certain  cases.  The  general  weakness  which  takes 
place  in  hunger  almost  instantaneously,  is  sympathetic  ; 
the  alteration  of  nutrition  has  not  had  time  to  produce  it 
The  same  is  true  with  regard  to  the  sudden  increase  of 
the  forces  which  results  from  the  contact  of  the  aliments 
upon  the  mucous  surface  of  this  viscus,  an  increase  which 
cannot  be  attributed  to  the  passage  of  the  chyle  into  the 
blood,  which  has  not  yet  had  time  to  take  place. 

I think  the  stomach  owes  this  important  part  in  the 
sympathies  principally  to  its  mucous  surface.  In  fact, 
1st,  its  serous  surface  has  no  connexion  with  it,  since  it  is 


MUCOUS  SYSTEM. 


125 


there  of  the  same  nature  as  in  all  the  rest  of  the  perito-  * 
neum,  besides  in  what  is  called  inflammation  of  the  abdo- 
men, and  in  which  this  serous  surface  is  especially  affect- 
ed, we  do  not  observe  such  numerous  sympathetic  rela- 
tions. 2d.  The  fleshy  coat  appears  to  be  the  same  as  that 
of  the  whole  intestinal  canal ; why  then  should  it  have 
diflferent  influences  ? 3d.  As  it  respects  blood-vessels  and 

nerves  of  the  ganglions,  the  stomach  is  nearly  organized 
like  the  rest  of  the  alimentary  tube.  4th.  It  has  besides 
the  par  vagum ; but  is  this  nerve  alone  capable  of  producing 
such  numerous  phenomena  ? It  can  contribute  to  them  ; 
but  certainly  the  peculiar  modifications  which  it  experi- 
ences in  the  mucous  surface,  the  peculiar  nature  of  this 
membrane  contribute  also  much  to  it.  No  membrane  is 
organized  like  that  of  the  stomach.  Though  we  do  not 
see  perfectly  at  first  view  its  organic  differences,  reflection 
is  sufficient  to  convince  us  of  them  ; thus  on  the  one  hand 
no  one  separates  so  great  a quantity  of  fluid,  and  on  the 
other  none  furnishes  one  of  a nature  analogous  to  that  of 
the  gastric  juice. 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  MUCOUS  SYSTEM. 


I.  State  of  the  Mucous  System  in  the  First  *t2ge. 

The  development  of  the  mucous  system  follows  in 
general  the  laws  of  that  of  the  organs  to  which  it  belongs. 
Early  in  the  gastric  apparatus,  later  in  the  pulmonary  and 


126 


MUCOUS  SYSTEM. 


that  of  generation,  it  seems  in  its  growth  rather  to  obey 
the  impulse  it  receives,  than  to  give  one  to  what  sur- 
i’ounds  it,  an  arrangement  common  to  almost  all  the  sys- 
tems which  contribute  to  form  the  different  apparatus. 
Observe  in  fact  that  there  is  always  in  the  growth  certain 
parts  to  which  all  the  others  refer ; thus  in  the  cerebral 
apparatus,  the  early  size  of  the  brain  produces  that  of  the 
bones  of  the  cranium,  of  the  dura-mater,  the  pia-mater, 
the  arachnoides  and  the  vessels  ; thus  it  is  om  account  of 
the  spinal  marrow,  that  the  vertebral  canal  is  so  evident 
in  the  feetus  ; thus  all  the  serous  surfaces  have  a growth  in 
proportion  to  that  of  their  respective  organs,  &c.  &c.  I 
would  remark  however  that  the  early  growth  of  the  sys- 
tems which  are  only  to  follow  that  of  the  parts  to  which 
they  are  destined,  is  only  in  the  dimensions  of  length, 
breadth,  &c.  The  thickness  most  commonly  does  not 
correspond  with  these  dimensions.  Thus  the  bones  of 
the  cranium  though  broader  in  proportion  than  those 
of  the  pelvis  in  the  fo&tus,  are  not  thicker.  The  extent  of 
the  dura-mater  is  in  proportion  greater  than  that  of  the 
albuginea  which  belongs  to  the  same  system  5 but  the 
organization  is  no  further  advanced. 

In  the  foetus,  the  delicacy  of  the  mucous  texture  is  ex- 
treme, the  papillae  are  hardly  perceptible.  But  by  carry- 
ing the  hand  over  a mucous  surface,  we  feel  there  an 
extremely  delicate  velvet  and  such  as  is  not  equalled  by 
the  finest  velvet.  The  redness  of  this  system  is  not  then 
as  evident,  because  no  doubt  less  blood  penetrates  it,  as 
the  various  functions  which  are  afterwards  to  take  place 
upon  these  surfaces,  as  digestion,  the  excretions,  respira- 
tion, &c.  are  but  feeble  or  entirely  wanting.  At  this 
age,  the  quantity  of  blood  seems  to  be  in  an  inverse  ratio 
in  the  skin  and  in  these  surfaces.  The  mucous  red  is 
then  like  the  muscular,  of  a very  deep  tinge,  often  even 
livid,  on  account  of  the  nature  of  the  blood  circulating  in 
the  arteries.  Then  the  adhesions  of  the  raucous  texture  to 


MUCOUS  SYSTEM. 


127 


the  subjacent  cellular  are  less  ; those  especially  of  this 
last  with  the  surrounding  parts  are  very  slight ; thus  it  is 
very  easy  to  draw  out  whole  the  internal  portion  of  the 
intestines  of  the  foetus,  from  the  external  covering  that 
contains  it,  so  as  to  see  two  cylindrical  canals,  one  of 
which  is  muscular  and  serous,  the  other  cellular  and  mu- 
cous. The  stretching  destroys  in  this  experiment  all  the 
valvulas  conniventes,  and  the  small  intestines  are  as  smooth 
on  the  interior  as  the  large,  in  the  canal  artificially  ex- 
tracted. If  we  subject  this  canal  to  ebullition,  much 
more  scum  arises  from  it  than  in  the  adult ; this  scum  is 
white  and  never  green.  The  crisping  that  takes  place  a 
little  before  the  first  boiling,  diminishes  more  in  propor- 
tion the  length  of  the  canal,  and  consequently  appears  to 
be  stronger. 

At  birth,  when  respiration  and  digestion  suddenly  com- 
mence, the  secretions  increase,  the  mucous  system  ac- 
quires a remarkable  degree  of  activity.  It  is  instantly 
excited  powerfully  by  the  many  new  substances  with 
which  it  is  in  contact.  It  is  by  it  and  by  the  cutaneous 
system  that  bodies  foreign  to  ours  then  immediately  stim- 
ulate it,  and  so  much  the  more  efficaciously,  as  the  double 
surface  which  receives  the  excitement  is  not  accustomed 
to  it.  Then  the  red  blood  which  penetrates  the  mucous 
system,  gives  it  an  increase  of  energy  and  sensibility, 
which  renders  it  still  more  proper  to  receive  impressions. 
Thus  the  mucous  juices  which  till  then  stagnated  upon 
their  respective  surfaces,  without  fatiguing  and  irritating 
them,  are  suddenly  for  them,  on  account  of  their  increase 
of  sensibility,  stimulants  which  excite  them,  and  force 
the  subjacent  muscles  to  contract.  Then  the  urine  be- 
comes for  the  bladder  a cause  that  prom.otes  the  contrac- 
tion of  it.  A few  instants  after  birth,  all  the  openings 
in  which  the  mucous  membranes  begin,  open  and  permit 
to  escape  the  meconium,  the  urine  and  all  the  mucous 
juices.  This  internal  and  general  shock  that  empties  all 


12$ 


MUCOUS  SYSTEM, 


the  mucous  cavities,  renders  them  fit  to  become  the  seat 
of  the  great  functions  which  are  soon  to  take  place  in 
them. 

When  all  the  internal  functions  are  in  activity,  the  mu- 
cous surfaces  experience  no  more  sudden  changes,  analo- 
gous to  that  of  which  I have  spoken.  They  grow  like 
the  other  viscera  in  a slow  and  insensible  manner ; they 
preserve  for  a long  time  their  original  softness,  which  is 
remarkable,  especially  in  the  nose,  the  stomach,  &c.  and 
which  during  lactation,  is  not  adapted  in  the  infant,  to 
the  solid  substances  with  which  the  adult  is  nourished. 
Is  this  softness  the  cause  of  the  mucous  affections  which 
are  in  general  so  common  at  that  age  ? We  know  that 
then  the  mucous  juices  abound  ; the  pituitary  membrane 
is  more  moist  ; the  stomach  and  intestines  are  frequently 
affected  with  a species  of  catarrh  which  is  the  cause  of 
the  looseness  that  we  have  so  often  to  combat  in  infancy. 
The  membrane  of  the  bronchia  is  also  frequently  diseased. 
The  two  extreme  ages  of  life  resemble  each  other  by  the 
abundance  of  the  mucous  juices  secreted  upon  their  re- 
spective mucous  surfaces. 

In  youth  the  mucous  system  is  in  very  powerful  action. 
The  active  hemorrhages  of  this  system  are  very  frequent 
at  this  age ; those  of  the  nose,  the  bronchia  and  even  the 
-stomach  often  take  place  ; those  of  the  portions  of  this 
system,  subjacent  to  the  diaphragm,  are  then  less  com- 
mon. Observe  that  in  man,  hemorrhages  of  the  gastro- 
pulmonary  surface  are  infinitely  more  frequent  than  those 
of  the  genito-urinary  surface,  which  on  the  contrary,  are 
much  more  numerous  in  woman  in  whom  one  of  them  is 
natural  to  a part  of  this  surface,  viz.  menstruation. 

At  the  period  of  puberty,  the  development  of  the 
genital  parts  in  both  sexes,  gives  much  activity  to  a part 
of  the  genito-urinary  surface  ; then  menstruation  begins 
upon  that  of  the  womb  ; then  the  sensibility  of  the 
urethra  is  raised  in  order  to  feel  acutely  the  passage  ot 


MUCOUS  SYSTEM. 


129 


the  semen.  Observe  that  this  increase  of  energy  is  not 
attended  with  a weakness  of  the  other  parts,  as  happens 
in  many  cases  ; on  the  contrary,  all  the  systems,  all  the 
apparatus  seem  to  borrow,  from  the  force  wdiich  the  genital 
parts  acquire,  an  increase  of  action. 

II.  State  of  the  Mucous  System  in  the  subsequent 
^ges. 

In  the  years  which  succeed  youth,  the  mucous  system 
continues  to  grow,  thicken  and  become  firmer.  Its  vital 
energy  seems  still  to  predominate  for  some  time,  in  the 
superior  surfaces,  as  in  the  pituitary,  the  membrane  of 
the  bronchia,  &c. ; thus  the  affections  of  these  parts  are 
more  frequent  until  the  thirtieth  year.  But  as  we  ad- 
vance in  age,  the  abdominal  mucous  surfaces  appear  to 
predominate  over  the  othei's,  as  in  general  all  the  organs 
of  this  region  do. 

Besides,  a thousand  causes  in  the  course  of  life,  make 
the  state  of  the  mucous  system  vary.  We  do  not  find  it 
in  two  subjects,  with  the  same  shade  of  colour,  with  the 
same  density,  with  the  same  external  appearance.  By 
taking  any  surface  upon  many  subjects,  that  of  the  stomach, 
for  example,  we  easily  see  these  differences,  with  which 
we  must  be  struck  if  we  have  opened  dead  bodies  but 
ever  so  little. 

The  redness  of  the  mucous  texture  is  very  bright  until 
the  thirtieth  year  ; after  that,  it  begins  to  alter.  This  tex- 
ture becomes  more  and  more  pale  in  old  age ; the  blood 
enters  it  but  in  small  quantity  ; it  acquires  more  consis- 
tence and  density.  The  fingers  carried  over  it  no  longer 
perceive  that  softness,  that  velvet  so  remarkable  in  the 
first  age.  Its  forces,  which  grow  languid,  I'ender  diffi- 
cult, in  the  excretories,  the  exit  of  the  fluids  which  pass 
through  these  tubes  to  be  thrown  out.  Yet  the  mucous 
glands  still  secrete  their  fluids  in  very  great  abundance. 

VOL.  III.  17 


130 


MUCOUS  SYSTEM. 


Often  even  these  fluids  increase  in  proportion  which  con- 
stitutes the  catarrhal  affections,  so  common  in  old  age. 
But  these  affections  then  have  the  same  character  as  the 
functions  of  the  whole  system ; secretion  takes  place 
slowly  ; the  disease  is  always  chronic  ; most  often  It  ter- 
minates only  with  life. 

The  mucous  absorption  is,  at  this  age,  slow  and  diffi- 
cult, like  all  the  others  ; the  various  contagions  are  taken 
much  less  easily,  either  by  the  respiratory  surfaces,  or  by 
the  contact  of  contagious  miasmata  upon  the  neighbour- 
ing surfaces  of  the  skin.  The  chyle  slowly  absorbed, 
makes  the  digestive  periods  longer. 


SEROUS  SYSTEM. 


THIS  system,  the  name  of  which  I borrow,  like  that 
of  the  preceding,  from  the  fluid  that  constantly  lubricates 
one  of  its  surfaces,  is  always  like  it  arranged  in  the  form 
of  membranes,  and  never  in  fasciculi  like  the  muscular 
system,  or  in  round  bodies  like  the  glandular.  It  is  form- 
ed by  the  peritoneum,  the  pleura,  the  pericardium,  the 
arachnoides,  the  tunica  vaginalis,  &c.  The  term  serous 
membrane  will  then  be  very  often  used  to  designate  it. 
No  one,  I believe,  before  the  publication  of  my  Treatise 
on  the  Membranes,  had  considered  in  a general  manner 
these  organs,  which  perform  a less  important  part  in  the 
functions  than  the  mucous,  but  which  in  diseases  are 
almost  as  frequently  affected.  Pinel,  who  has  perceived 
the  analog}’  of  their  inflammations,  has  taken  this  system 
as  a character  of  one  of  the  classes  of  his  phlegmasiae. 


ARTICLE  FIRST. 

OF  THE  EXTENT,  FORMS,  AND  FLUIDS  OF  THE  SEROUS 
SYSTEM. 

The  serous  system  occupies  the  exterior  of  most  of 
the  organs  of  which  the  mucous  lines  the  interior  ; such 
are  the  stomach,  the  intestines,  the  bladder,  the  lungs, 


132 


SEROUS  SYSTEM. 


&c.  We  see  it  around  all  those  that  are  essential  to  life, 
as  around  the  brain,  the  heart,  all  the  gastric  viscera,  the 
testicles,  the  bladder,  &c.  It  does  not  form,  like  the  mu- 
cous sj'stem,  a surface  ever}nvhere  continuous  upon  the 
numerous  organs  on  which  it  is  spread.  But  it  is  always 
found  insulated  in  its  different  divisions  which  never 
have  any  communication.  The  number  of  these  divi- 
sions is  somewhat  considerable.  By  considering  in  one 
view  all  the  different  serous  surfaces,  w'e  see  that  as  a 
whole  they  exceed  the  mucous  surfaces  viewed  also  in 
a general  manner.  One  consideration  is  sufficient  to 
convince  us  of  it.  The  mucous  and  serous  surfaces  ac- 
company each  other  in  a very  great  number  of  parts, 
as  in  the  stomach,  the  intestines,  the  lungs,  the  bladder, 
the  gall-bladder,  &c.  so  as  to  exhibit  in  them  nearly  the 
same  extent.  But  on  the  one  hand,  the  mucous  surfaces 
extend  where  the  serous  are  not  met  with,  as  in  the  nasal 
fossa3,  the  oesophagus,  the  mouth,  &c.  &c.  ; and  on  the 
other,  there  is  a very  great  number  of  serous  surfaces 
existing  separately  from  the  mucous,  as  the  pericardium, 
the  arachnoides,  &c.  Now  if  we  compare  the  extent  of 
the  separate  serous  surfaces,  with  that  of  the  separate 
mucous  surfaces,  we  shall  see  that  the  first  is  much  greater 
than  the  other. 

These  considerations,  apparently  minute,  deserve  how- 
ever particular  attention,  on  account  of  the  relation  of 
functions  existing  between  these  two  surfaces  taken  as  a 
whole,  a relation  which  is  especially  connected  with  the 
exhalation  of  the  albuminous  fluids  produced  by  one, 
and  with  the  secretion  of  the  mucous  fluids,  of  which 
the  other  is  the  seat.  Besides,  in  examining  the  extent 
of  each  serous  membrane  in  particular,  we  ^ see  great 
varieties  from  the  peritoneum  which  has  the  greatest  sur- 
face, to  the  tunica  vaginalis  which  has  the  least. 

Tlie  serous  surface  taken  as  a whole,  compared  with 
the  cutaneous  surface,  is  also  evidently  superior  to  it  in 


SEROUS  SYSTEM. 


13S 


extent ; so  that  in  this  respect,  the  quantity  of  albuminous 
fluids  constantly  exhaled  with#n,  appears  to  be  much 
more  considerable  than  that  of  the  fluid  which  is  inces- 
santly thrown  oAF  by  insensible  transpiration  ; I say  in 
this  respect,  for  difierent  circumstances,  by  increasing  the 
action  of  the  cutaneous  organ,  can  re-establish  the  equili- 
brium in  the  exhalation  of  these  two  fluids,  one  of  which 
re-enters  by  absorption  into  the  circulation,  and  the  other 
is  wholly  excrementitious.  I do  not  know  even  if  the 
pulmonary  and  cutaneous  exhalations  united  are  not  less 
tlian  those  which  take  place  upon  the  serous  surfaces. 

Every  serous  membrane  represents  a sac  without  an 
opening,  spread  upon  the  respective  organs  that  it  em- 
braces, and  which  are  sometimes  very  numerous,  as  in 
the  case  of  the  peritoneum,  sometimes  single,  as  in  the 
case  of  the  pericardium,  covering  these  organs  so  that 
they  are  not  contained  in  its  cavity,  and  so  that  if  it  was 
possible  to  dissect  them  from  their  surface,  we  should 
have  this  cavity  whole.  This  sac  has  in  this  respect  the 
same  arrangement  as  those  night  caps,  which  are  folded 
within  themselves  ; a trifling  comparison,  but  which  gives 
an  accurate  idea  of  this  sort  of  membranes. 

From  this  general  arrangement,  it  is  easy  to  under- 
stand that  the  serous  membranes  are  never  opened  to 
permit  the  vessels  and  nerves  to  penetrate  the  respective 
organs  to  which  they  go  or  from  which  they  come  oflf, 
but  that  they  always  wind  round  them  and  accompany 
them  to  the  organ,  and  thus  form  for  them  a sheath  which 
prevents  them  from  being  contained  in  their  cavities ; 
this  removes  the  danger  of  infiltration  of  serum  which 
lubricates  them,  an  infiltration  which  would  take  place 
through  the  neighbouring  cellular  texture,  especially  if 
they  were  dropsical ; if,  as  in  the  fibrous  membranes,  they 
were  pierced  with  foramina  for  the  passage  of  these  ves- 
sels and  nerves.  This  arrangement,  exclusively  remark- 
able in  the  membranes  of  which  we  are  treating,  and  in 


134 


SEROUS  SYSTEM. 


the  synovial  ones,  is  evident  at  the  entrance  of  the  ves- 
sels of  the  lungs,  the  spleen,  the  intestines,  the  stomach, 
the  testicles,  &c.  We  see  it  very  well  in  the  arachnoides, 
a membrane  essentially  serous,  as  I have  demonstrated 
elsewhere. 

•From  the  general  idea  that  we  have  given  of  these 
membranes,  it  is  also  easy  to  understand  how  almost  all 
are  composed  of  two  distinct  parts,  though  continuous, 
and  embracing,  the  one  the  internal  surface  of  the  cavity 
where  they  are  found,  the  other  the  organs  of  this  cavity; 
thus  there  is  a costal  and  pulmonary  pleura,  a cranial  and 
cerebral  arachnoides,  one  portion  of  peritoneum  spread 
upon  the  gastric  organs,  and  another  upon  the  abdominal 
parietes,  a free  portion  of  the  pericardium,  and  one  ad- 
hering to  the  heart.  The  same  arrangement  exists  in  the 
testicles,  &c. 

Though  the  serous  membranes  may  be  separate,  yet 
there  sometimes  exists  communications  between  them  ; 
that  for  example  of  the  cavity  of  the  omentum  with  that 
of  the  peritoneum,  that  of  the  cavity  of  the  arachnoides 
with  the  cavity  of  the  membrane  which  lines  the  ventri- 
cles by  the  canal  that  I have  discovered,  and  the  external 
orifice  of  which  is  seen  below  and  at  the  posterior  part 
of  the  corpus  callosum  ; whilst  the  internal  one  is  seen 
above  the  pineal  gland,  between  the  two  rows  of  small 
round  bodies  which  are  usually  found  in  this  place. 

There  is  but  one  example  of  continuity  between  the 
serous  and  mucous  membranes,  that  which  exists,  by 
means  of  the  Fallopian  tube,  between  the  peritoneum 
and  the  uterine  surface.  How  does  the  respective  nature 
of  the  two  membranes  change  here  ? 

Free  Surface  of  the  Serous  Membranes. 

Every  serous  membrane  has  one  of  its  two  surfaces 
free,  everywhere  contiguous  to  itself,  and  the  other  adher- 
ing to  the  neighbouring  oi’gans.  The  first  is  remarkable 


SEROUS  SYSTEM. 


135 


for  its  polish,  which  especially  distinguishes  this  system 
and  the  following,  from  all  the  other  membranes.  All  the 
organs  which  exhibit  this  arrangement  owe  it  to  the  cover- 
ing they  borrow  from  it.  The  liver  ceases  to  be  smooth 
and  shining  at  its  diaphragmatic  edge  where  the  perito- 
neum abandons  it.  There  is  in  this  respect  a great  dif- 
ference in  the  appearance  of  the  anterior  and  posterior 
face  of  the  csecum.  The  bladder  is  rough  wherever  the 
peritoneal  covering  is  wanting.  The  cartilages  of  the 
ribs  have  not  the  polish  of  those  of  the  articulations  which 
the  synovial  membrane  covers. 

Does  this  remarkable  attribute  of  the  serous  membranes 
depend  on  the  compression  exerted  upon  them  ? Their 
situation  in  places  where  they  are  exposed  to  continual 
friction,  would  seem  to  make  it  probable.  Bordeu  thought 
so,  when  he  said  that  all  the  parts  of  the  abdomen  are  origi- 
nally covered  with  cellular  texture,  which  by  pressure  is 
afterwards  changed  into  membranes  ; so  that  the  perito- 
neum is  formed  partially  upon  each  gastric  organ,  and  its 
different  parts  give  birth,  by  uniting,  to  the  general  mem- 
brane. This  explanation  of  the  formation  of  the  perito- 
neum is  applicable,  according  to  him,  to  the  pleura,  the 
pericardium,  and  all  the  analogous  membranes.  But  if  this 
is  the  progress  of  nature,  1st,  why,  whatever  be  the  period 
at  which  we  examine  the  foetus,  do  we  find  the  perito- 
neum and  the  serous  membranes  as  much  developed  in 
proportion,  as  their  corresponding  organs  ? 2d.  How  are 

the  numerous  folds  of  these  membranes  formed,  such  as 
the  mesentery,  the  omentum,  &c.  ? 3d.  Why  are  thei-e 

parts  where  they  do  not  exist  though  they  are  exposed 
to  as  great  friction  as  that  of  the  parts  where  they  are 
found  ? Why,  for  example,  are  the  sides  of  the  bladder 
destitute  of  it,  whilst  it  covers  its  superior  part  ? 4th. 
Why  does  it  not  also  form  serous  surfaces  around  the 
great  vessels  of  the  arm,  the  thigh,  &c.  which  impart  to 
the  neiorhbourina:  orsrans  an  evident  motion  ? 5th.  Why 


136 


[SEROUS  SYSTEM. 


does  not  the  thickness  of  the  serous  membranes  increase 
Avhere  the  motion  is  strongest  and  diminish  where  it  is 
weakest?  Why  for  example  does  the  thickness  of  the 
tunica  vaginalis  equal  that  of  the  pericardium  ? 6th. 
How  can  friction  internally  produce  an  organized  body, 
whilst  externally  it  constantly  disorganizes  the  epider- 
mis ? 7lh.  How  can  we  associate  the  vascular  lymphatic 
texture  of  the  serous  membranes  with  the  pressure  that 
produces  them  ? The  impossibility  of  resolving  these 
numerous  questions  proves,  that  it  is  not  to  mechanical 
pressure  that  must  be  attributed  the  formation  of  the 
serous  membranes  and  the  polish  of  their  surface ; that 
their  mode  of  origin  is  the  same  as  that  of  the  other 
organs ; that  they  commence  and  are  developed  with 
them  ; that  this  polish  is  an  evident  result  of  their  organi- 
zation, as  the  mucous  papillae  depend  upon  the  texture  of 
the  surfaces  to  which  they  belong.  What  would  be  said 
of  a system  in  which  these  papillae  should  be  attributed 
to  the  pressure  of  the  aliments  upon  the  stomach,  of  the 
urine  on  the  bladder,  the  air  on  the  pituitary  mem- 
brane, &c.  ? 

The  free  surface  of  the  serous  membranes  separates 
entirely  from  the  neighbouring  organs  those  upon  which 
these  membranes  are  spread ; so  that  they  are  to  these 
organs  real  boundaries,  barriers,  if  I may  use  the  term, 
or  integuments,  if  it  'should  be  preferred,  very  different 
however  from  those  which  are  external.  Observe  in  fact 
that  all  the  principal  viscera,  the  heart,  the  lungs,  the 
brain,  the  gastric  viscera,  the  testicles,  &c.  limited  by  their 
serous  covering,  suspended  in  the  middle  of  the  sac  that 
it  forms,  only  communicate  with  the  adjacent  parts  where 
their  vessels  enter  ; everywhere  else  there  is  contiguity 
and  not  continuity. 

This  insulation  of  position  coincides  very  well  with 
the  insulation  of  vitalit}’^  which  is  remarked  in  all  the 
organs,  and  especially  in  those  that  we  have  just  noticed. 


SEROUS  SYSTEM. 


137 


Each  has  Its  peculiar  life,  which  is  the  result  of  a parti- 
cular modification  of  its  vital  forces,  a modification  which 
necessarily  establishes  one  in  the  circulation,  nutrition 
and  temperature.  No  part  feels,  is  moved  and  nourished 
like  another,  unless  it  belongs  to  the  same  system.  Each 
organ  executes  on  a small  scale  the  phenomena  which 
take  place  on  a large  one  in  the  economy  ; each  takes 
from  the  circulation  the  aliment  that  is  proper  for  it, 
digests  it,  throws  back  into  the  mass  of  blood,  the  portion 
which  is  heterogeneous  to  it,  and  appropriates  to  itself 
that  which  can  nourish  it ; it  is  digestion  in  miniature. 
No  doubt  the  ancients  wished  to  give  an  idea  of  this 
truth  which  has  been  so  well  explained  by  Bordeu,  when 
they  said  that  the  womb  was  a living  animal  within 
another.  A very  important  use  then  of  the  serous  mem- 
branes is  to  contribute,  by  rendering  independent  the 
position  of  their  respective  organs,  to  the  independence 
of  the  vital  forces,  life  and  functions  of  these  organs. 

Let  us  not  forget  to  consider  under  the  same  point  of 
view,  the  moist  atmosphere  with  which  they  are  con- 
stantly surrounded,  an  atmosphere  analogous  to  that  which 
the  cellular  texture  forms  for  various  other  organs.  In 
this  atmosphere  all  the  morbific  emanations  of  the  organ 
go  and  are  lost,  if  we  may  so  say^  without  these  emana- 
tions injuring  the  other  organs.  We  have  seen  that  this 
atmosphere  in  the  cellular  system  is  sometimes  the  seat 
of  phenomena  wholly  different,  and  serves  to  transmit 
diseases  from  one  organ  to  another.  Now  the  serous 
membranes  are  a barrier  much  less  easily  surmounted, 
because  they  have  not  filaments  which  go  from  one  organ 
to  another,  there  is  only  contiguity  as  I have  said,  with 
the  organs  that  they  surround.  We  very  rarely  see  in 
the  abdomen  a disease  of  the  liver  communicated  to  the 
intestines,  one  of  the  spleen  passing  to  the  stomach,  &c. 

The  smoothness  of  the  free  surface  of  the  serous  system 
greatly  facilitates  the  motions  of  the  organs  which  it 
VOL.  III.  18 


138 


SEROUS  SYSTEM. 


covers.  We  have  already  observed  that  nature  employs 
two  principal  means  for  this  object,  viz.  the  membranes 
and  the  cellular  texture.  By  distributing  externally  the 
second  of  these  means,  it  has  designed  the  first  especially 
for  internal  motions.  The  smoothness  and  moisture  of 
the  serous  surfaces  are  singularly  favourable  for  them. 
These  internal  motions  are  usually  regarded  only  in  ah 
insulated  manner,  as  relating  to  the  functions  of  the  organ 
that  executes  them,  as  in  relation  to  the  circulation  for 
the  heart,  respiration  for  the  lungs,  digestion  for  the 
stomach,  &c.  But  they  should  also  be  considered  in  a 
general  manner ; they  should  be  regarded  as  carrying 
through  the  whole  machine  a continual  excitement  which 
supports  and  animates  the  forces  and  the  action  of  all  the 
organs  of  the  head,  the  chest  and  the  abdomen,  which 
receive  less  sensibly  than  the  organs  of  the  extremities, 
the  influence  of  external  motions.  It  is  these  internal 
motions  that  excite,  sustain,  and  develop  within,  the  nutri- 
tive phenomena,  as  the  motions  of  the  thigh,  the  arm,  &c. 
without,  favour  the  nutrition  of  the  muscles  which  are 
found  there ; this  is  seen  very  evidently  in  bakers  and 
other  mechanics  who  exert  more  particularly  this  or  that 
part.  It  is  thus  that  the  serous  membranes  contribute 
indirectly  to  the  nutrition  and  growth  of  their  respective 
viscera  ; but  they  never  have  a direct  influence  upon  this 
nutrition,  because  their  organization  and  life  are  different 
from  the  life  and  organization  of  these  viscera. 

The  free  surface  of  the  serous  system  differs  essentially 
from  that  of  the  mucous,  in  this,  that  it  contracts  fre- 
quent adhesions.  The  pleura  is  of  all  the  serous  organs, 
that  in  which  these  adhesions  are  the  most  evident.  We 
find  almost  as  many  dead  bodies  in  which  they  exist,  as 
we  do  those  in  which  they  do  not.  Next  to  the  pleura 
is  the  peritoneum,  then  the  pericardium,  then  the  tunica 
vaginalis,  then  the  arachnoides,  which  is  that  of  all  the 
serous  surfaces  in  which  adhesions  are  the  least  frequent. 


SEROUS  SYSTEM. 


139 


though  I have  observed  them  in  it.  These  adhesions 
exhibit  many  varieties  \vhich  can  be  studied  best  on  the 
pleura,  which  are  as  follows. 

1st.  Sometimes  the  costal  and  pulmonary  portion  are 
so  identified  at  many  points  or  in  every  part,  that  they 
make  but  a single  membrane,  and  are  united  as  closely 
as  the  two  edges  of  the  lip  in  a hare-lip  that  has  been 
operated  upon  with  success.  2d.  At  other  times  the  ad- 
hesion is  so  slight,  that  the  least  effort  is  sufficient  to 
destroy  it.  I have  many  times  noticed  this  fact  in  the 
pericardium.  I saw  it  once  in  the  tunica  vaginalis  of  a 
man  who  had  been  operated  upon  for  hydrocele  by  means 
of  injection,  at  the  time  I was  surgeon  for  operations  at 
the  Hotel  Dieu.  Separated  then  from  each  other,  the  two 
surfaces  were  uneven  ; they  lost  their  polish.  3d.  Fre- 
quently between  the  costal  and  pulmonary  portion  of  the 
pleura,  between  the  surfaces  of  the  peritoneum,  &c.  there 
are  several  elongations  of  various  lengths,  which  form  a 
kind  of  loose  bridles,  traversing  the  serous  cavity,  having 
the  same  organization  and  polish  as  the  membrane  of 
which  they  appear  a kind  of  fold,  containing  in  their 
interior  a species  of  small  canal,  because  they  are  formed 
by  two  layers  united  together,  resembling  very  much  the 
elongation  of  the  synovial  membrane  of  the  knee,  which 
goes  fi’om  the  posterior  part  of  the  patella  to  the  space 
between  the  condyles  of  the  femur,  having  also  an  appear- 
ance analogous  to  the  different  natural  folds  of  the  peri- 
toneum. We  can  hardly  conceive  that  these  filaments  so 
regularly  organized  can  result  from  inflammation.  I am 
inclined  to  believe  that  they  are  owing  to  an  original  con- 
formation. 4th.  Frequently  between  the  two  portions  of 
the  pleura,  there  are  seen  many  other  elongations  wholly 
different,  which  are  not  smooth,  and  do  not  form  canals, 
but  which  appear  to  be  flocculent  and  really  analogous  to 
the  cellular  layers ; so  that  where  they  exist  it  may  be 
said,  that  the  membi'ane  is  entirely  changed  into  this  tex- 


140 


SEROUS  SYSTEM. 


ture,  which  is  besides,  as  we  shall  see,  the  essential  base 
of  its  organization.  5th.  I do  not  speak  of  the  adhesions 
produced  by  false  membranes,  by  albuminous  flakes,  inter- 
mediate to  the  two  portions  of  a serous  surface,  &c.  These 
adhesions  are  to  a certain  point  foreign  to  these  surfaces. 

II.  Jidhereni  Surface,  of  the  Serous  System. 

The  external  surface  of  the  serous  membranes  adheres 
almost  everywhere  to  the  neighbouring  organs  ; it  is  rare 
in  fact  to  see  these  membranes  detached  on  both  sides. 
The  arachnoides  at  the  basis  of  the  cranium,  and  some 
other  examples  are  exceptions.  This  adhesion  of  the 
serous  membranes  to  their  respective  organs,  is  wholly 
different  from  that  of  the  fibrous  membranes.  In  this 
last,  the  passage  of  the  vessels  so  unites  the  two  parts, 
that  their  organization  seems  to  be  common,  and  when 
one  is  removed,  the  other  almost  always  dies,  as  is  seen 
in  the  periosteum  in  relation  to  the  bones,  &c.  On  the 
contrary,  every  serous  membrane  is  almost  foreign  to  the 
organ  it  surrounds  ; their  organization  is  different.  The 
following  are  proofs  of  it ; 

1st.  We  very  often  see  these  membranes  abandon  and 
cover  again  successively  their  respective  organs ; thus 
the  bi'oad  ligaments,  at  a great  distance  from  the  womb 
in  the  ordinary  state,  are  to  it  like  a serous  membrane 
during  preg-nancy.  An  intestine  when  distended  borrows 
from  the  mesentery  a covering  that  quits  it  when  it  con- 
tr.acts.  The  omentum  is  by  turns,  as  Chaussier  has  well 
observed,  a loose  membrane  in  the  abdomen  and  a cover- 
ing of  the  stomach.  The  peritoneal  envelope  of  the 
bladder  often  leaves  it  almost  entirely.  Has  not  the  her. 
nial  sac  of  those  enormous  tumours  of  gastric  viscera 
originally  served  to  line  the  parietes  of  the  abdomen? 
Now  it  is  evident,  since  the  different  organs  can  exist 
separate  from  their  serous  membranes,  that  there  is  no 


SEROUS  SYSTEM. 


141 


connexion  between  their  organization.  2d.  It  is  always  a 
loose  texture,  easily  stretched  in  every  direction,  that 
serves  as  a means  of  union,  and  never  a sanguineous  vas- 
cular system,  as  in  most  of  the  other  adhesions.  3d. 
The  afiection  of  an  organ  is  not  a necessary  consequence 
of  that  of  its  serous  membrane,  and  reciprocally  the  organ 
is  often  affected  and  the  membrane  does  not  become  dis- 
eased. For  example,  in  the  operation  for  hydrocele,  the 
testicle  remains  almost  always  sound  in  the  midst  of  the 
inflammation  of  its  tunica  vaginalis.  The  inflammation 
of  the  mucous  membrane  of  the  intestines  is  not  a conse- 
quence of  that  of  their  peritoneal  covering  ; and  recipro- 
cally in  the  various  acute  catarrhal  aflections  of  the  organs 
with  a mucous  membrane  within  and  a serous  one  with- 
out, this  last  is  never  found  inflamed.  In  a word,  the 
affections  of  the  mucous  membranes  are  everywhere  very 
distinct  from  those  of  the  serous,  though  most  commonly 
both  contribute  to  the-  formation  of  the  same  organ.  It 
is  evident  that  a line  of  demarcation  so  great  in  the  affec- 
tions supposes  one  of  course  in  the  organization.  The 
life  of  the  serous  membranes  then  is  entirely  distinct 
from  that  of  their  corresponding  organs. 

Yet  there  ai’e  cases  where  these  membranes  do  not  pre- 
sent this  loose  adhesion,  and  where  they  become  so  united 
to  the  organs  which  they  line,  that  frequently  the  most 
delicate  scalpel  cannot  separate  them.  Observe  the  tunica 
vaginalis  on  the  albuginea,  the  arachnoides  on  the  dura- 
mater,  and  other  membranes  which  form  what  I have 
called  the  sero-fibrous,  &c.  ; such  is  the  connexion  of 
these  different  surfaces,  that  many  have  been  mistaken  to 
the  present  time  for  a single  membrane.  There  is  how- 
ever no  more  identity  in  the  organization,  than  where  the 
serous  membranes  are  more  loosely  attached  to  their  re- 
spective organs,  as  is  seen  in  the  peritoneum,  the  pleura, 
&c.  Diseases  sometimes  make  tliis  difference  very  evi- 
dent. I have  seen  the  arachnoides  in  a subject  that  had 


142 


SEROUS  SYSTEM. 


been  affected  with  a chronic  inflammation,  evidently  thick- 
ened on  the  internal  surface  of  the  dura-mater,  without 
this  having  experienced  the  slightest  alteration  ; it  waS 
detached  without  difiiculty  and  torn  with  great  ease. 

III.  Serous  Fluids. 

Every  serous  membrane  is  moistened  on  its  internal 
surface  by  a fluid  almost  the  same  as  the  serum  of  the 
blood.  The  exhaling  orifices  constantly  pour  it  out  and 
it  is  constantly  taken  up  by  the  absorbents.  Its  quantity 
varies.  A mere  dew  in  the  natural  state,  it  is  exhaled  in 
vapour  when  the  serous  surfaces  are  laid  bare  and  allow 
the  air  to  dissolve  it.  It  is  in  general  more  abundant  in 
dead  bodies  than  in  the  living,  because  on  the  one  hand 
the  transudation  which  the  tonic  forces  prevent,  then 
easily  takes  place  from  the  destruction  of  these  forces, 
and  supplies  the  place  of  the  vital  exhalation,  by  trans- 
mitting mechanically  by  their  weight,  the  fluids  of  the 
surrounding  organs  to  the  different  serous  cavities,  and 
because  on  the  other  hand,  this  destruction  of  the  tonic 
forces  prevents  every  kind  of  absorption  ; hence  the 
stagnation  and  accumulation  of  this  fluid.  We  know  to 
wliat  an  extent  this  increases  in  various  dropsies,  espe- 
cially in  that  of  the  abdomen. 

Does  this  quantity  vary  according  to  the  different  states 
of  the  organs  which  the  serous  membranes  cover  ? It 
has  been  long  said,  that  the  synovia  is  exhaled  in  greater 
abundance  in  the  motion  of  the  articulations,  than,  in  their 
state  of  rest.  I have  no  data  on  this  point  founded  upon 
experiment ; but  I am  certain  that  I have  many  times  ob- 
served in  living  animals,  that  the  exhalation  of  the  serous 
surface  of  the  abdomen  does  not  increase  during  diges- 
tion, or  at  least  if  it  is  greater,  absorption  becomes  more 
active,  and  thus  the  surface  of  the  peritoneum  is  not  more 

moist  than  at  another  time.  I have  opened  the  thorax  of 

} 

') 


I 


SEROUS  SYSTEM. 


143 


many  small  guinea-pigs,  after  having  first  made  them  run 
a long  time  in  the  chamber  in  order  to  accelerate  their 
respiration,  and  I have  not  observed  greater  moisture  on 
the  pleura.  Yet  it  cannot  be  doubted,  as  we  shall  see, 
that  the  quantity  of  the  serous  fluids  may  be  very  variable 
in  the  difierent  acute  diseases  ; that  the  serous  membranes 
exhale  more  or  less  of  them,  according  to  the  manner  in 
which  they  are  sympathetically  afiected. 

In  the  first  periods  of  inflammations,  in  which  the  ex- 
halants  of  the  serous  membranes  are  full  of  blood  which 
is  preternatu rally  introduced  into  them,  the  serum  does 
not  ooze  in  greater  quantity  from  their  free  surface.  Then 
as  they  are  on  the  one  hand  very  sensible,  and  very  dry 
on  the  other,  the  motions  of  the  organs  that  they  cover 
are  v/onderfully  painful.  It  is  in  these  first  periods  that 
adhesions  take  place.  If  they  are  not  formed  either  on 
account  of  the  motion,  or  for  other  reasons,  and  if  resolu- 
tion of  the  inflammation  does  not  take  place,  then  hap- 
pens to  the  serous  surfaces  what  happens  to  a wound  not 
united ; they  suppurate,  but  this  suppuration  is  never  at- 
tended with  ulceration  or  erosion  of  their  substance. 
However  abundant  the  purulent  collections  may  be,  these 
membranes  always  remain  sound ; their  texture  is  only 
more  or  less  thickened ; pus  is  thrown  out  by  them,  like 
the  natural  serous  fluids,  that  is  by  exhalation.  We  know 
how  much  this  fluid  varies  in  consistence  from  milky 
serum,  to  the  thickest  false  membrane  that  adheres 
strongly  to  the  surface  that  has  exhaled  the  materials  of  it. 

The  nature  of  the  fluids  of  the  serous  system  is  very 
evidently  albuminous.  The  instant  one  of  the  mem- 
branes of  this  system  is  plunged  into  boiling  water,  I 
have  observed  that  it  is  covered  with  a white  layer  which 
is  concrete  albumen,  and  which  being  removed  some 
time  after,  leaves  the  surface  nearly  of  its  original  col- 
our. All  the  substances  which  coagulate  albumen  pro- 
duce a similar  layer  upon  the  serous  surfaces.  The  ex- 


144 


SEROUS  SYSTEM. 


periments  of  Hcwson,  who  has’  collected  some  spoonsful 
of  these  fluids  in  the  great  animals,  confirm  their  albumi- 
nous nature.  Rouelle  and  Fourcroy  who  have  analyzed 
the  water  of  dropsies  have  also  found  albumen  predomi- 
nant in  it.  Observe  upon  this  subject  that  all  the  white 
flakes  swimming  in  this  water,  that  the  false  membranes 
that  form  in  it  and  the  white.,  fluids  which  give  it  the  ap- 
pearance of  milk,  appear  to  be  only  albumen  which  is 
found  in  different  degrees  of  consistence.  It  might  be 
said  that  the  heat  of  inflammation  has  produced  the  same 
phenomenon  during  life,  that  common  caloric  does  upon 
the  white  of  an  egg,  the  witer  of  dropsies,  &c.  I shall 
not  treat  of  the  other  accessory  principles  that  enter  into 
the  composition  of  the  serous  fluids. 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  SEROUS  SYSTEM. 

The  first  characters  of  the  structure  of  these  mem- 
branes are  a white,  shining  colour,  less  brilliant  than  that 
of  the  aponeuroses  ; a variable  thickness,  very  evident 
upon  the  liver,  the  heart,  the  intestines,  &c.  hardly  dis- 
coverable upon  the  arachnoides,  the  omentum,  &c.  ; a re- 
markable transparency  whenever  these  membranes  are 
raised  for  a considerable  extent,  or  are  examined  where 
they  are  detached  on  both  sides,  as  on  the  omentum. 

All  have  but  a single  layer  which  it  is  possible,  at  the 
places  where  it  is  thick,  to  raise  from  the  cellular  layers, 
but  which  can  never  be  neatly  divided  into  two  or  three 
portions  ; a character  essentially  distinct  from  those  of 
the  mucous  membranes.  The  action  of  a blister  on  their 


SEROUS  SYSTEM. 


145 


external  surface  first  laid  bare,  for  example,  on  a portion 
of  intestine  drawn  out  in  a living  animal,  does  not  make 
a pellicle  rise  upon  it,  as  upon  the  skin,  a pellicle  under 
which  the  serum  is  collected.  I have  frequently  made 
this  attempt.  What  is  the  immediate  structure  of  this 
single  layer  of  the  serous  membranes  ? I shall  now  ex- 
amine it. 

I.  Cellular  Nature  of  the  Serous  Texture. 

Every  system  is  in  general,  as  we  have  thus  far  seen, 
an  assemblage,  1st,  of  common  parts,  which  are  especially 
the  cellular  texture,  the  blood  vessels,  the  exhalants,  the 
absorbents  and  the  nerves,  which  form  as  we  have  said 
the  outline  and  the  frame  of  it,  if  I may  so  express  my- 
self ; 2d,  of  a peculiar  fibre  formed  by  a substance  which 
is  deposited  in  this  outline,  by  gelatine,  for  example,  for 
the  cartilages,  by  gelatine  and  phosphate  of  lime  for  the 
bones,  by  fibrin  for  the  muscles,  &c.  That  which  makes 
these  organs  resemble  each  other  then  is'  the  cellular 
organ,  the  vessels  and  the  nerves ; that  which  distin- 
guishes them,  is  their  peculiar  texture,  which  depends 
itself  upon  a peculiar  nutritive  matter.  A bone  would 
become  a muscle,  if,  without  changing  its  texture  at  all, 
nature  had  imparted  to  it  the  faculty  of  secreting  fibrin, 
and  of  encrusting  itself  with  it,  instead  of  separating  the 
phosphate  of  lime  and  being  penetrated  with  it.  But 
the  serous  system  does  not  appear  to  have  in  it  a distinct 
nutritive  matter,  and  consequently  a peculiar  texture.  It 
is  only  formed  of  the  mould,  the  outline  of  others,  and 
is  not  penetrated  by  a substance  that  characterizes  it. 
Almost  wholly  cellular,  it  does  not  differ  from  this  sys- 
tem in  its  common  form,  except  by  a degree  of  conden- 
sation, by  an  approximation  and  union  of  cells  which  are 
found  scattered  in  the  ordinary  state. 

The  following  are  the  proofs  that  the  texture  of  the 
serous  system  is  wholly  cellular.  1st.  There  is  an  iden- 

voL.  nr.  19 


146 


SEROUS  SYSTEM. 


lity  of  nature  where  there  is  an  identity  of  functions  and 
diseases  ; now  it  is  evident  that  the  uses  of  these  mem- 
branes and  of  the  cellular  texture,  as  it  respects  the  con- 
tinual absorption  and  exhalation  of  lymph  are  completely 
the  same,  and  that  the  phenomena  of  the  various  dropsies 
are  common  to  them,  with  the  difference  only  of  the 
effusion  in  the  one  and  infiltration  in  the  other.  2d.  The 
inflation  of  air  into  the  texture  subjacent  to  these  mem- 
branes terminates  by  bringing  them  almost  to  a cellular 
state,  when  it  succeeds  and  is  pushed  for  some  time  ; an 
experiment  which  is  frequently  very  difficult.  3d.  Mace- 
ration, as  has  been  remarked  by  Haller,  produces  at  length 
the  same  effect,  but  in  a still  more  evident  manner.  4th. 
The  various  cysts,  hydatids,  &c.  whose  appearance,  tex- 
ture and  nature  even  are  entirely  the  same  as  in  the  serous 
membranes,  as  we  have  seen,  always  arise  in  the  midst 
of  tlie  cellular  texture,  grow  at  its  expense  and  are  wholly 
formed  of  it.  5th.  No  fibre  is  found  in  the  serous  mem- 
bi'anes  ; a character  that  distinguishes  it  from  all  the  other 
organs  and  analogous  to  that  of  the  cellular  texture. 

To  these  various  proofs  of  analogy,  of  identity  even  of 
the  cellular  and  serous  systems,  we  can  add  the  action  of 
different  reagents,  which  give  results  precisely  similar  in 
both.  1st.  Every  serous  membrane  when  dried,  becomes 
transparent,  does  not  turn  yellow  like  the  fibrous  and 
the  mucous  membranes,  preserves  a pliability  foreign  to 
these  membranes  when  dried,  and  gradually  resumes 
its  original  state  when  it  is  immersed  in  water.  2d.  It 
becomes  putrid  much  slower  than  the  mucous  surfaces, 
the  muscular  layers,  the  glands,  &c.  This  is  remarkable 
in  the  abdomen,  upon  the  peritoneum  which  is  frequently 
almost  untouched,  when  every  thing  is  putrid  around  it, 
as  may  be  seen  by  removing  it ; for  its  transparency 
would  make  you  believe  at  first  viev/  that  it  was  altered, 
if  you  examine  it  upon  the  fleshy  and  mucous  surfaces. 
3d.  Maceration  at  the  ordinary  temperature  of  cellars,  re- 


SEROUS  SYSTEM. 


147 


duces  with  great  difficulty  to  a pulp  the  serous  mem- 
branes. The  omentum,  the  finest  and  most  delicate  of 
these  membranes  has  resisted  it  for  a very  long  time  in 
my  experiments.  This  phenomenon  is  particularly  strik- 
ing when  compared  with  the  maceration  of  tendons  which 
are  so  resisting,  and  which  support  such  great  efforts 
during  life.  These  become  pulpy  in  water  before  the 
omentum  is  touched.  The  same  phenomenon  takes  place 
with  regard  to  all  the  other  serous  surfaces.  4th.  In  boil- 
ing water,  these  surfaces  acquire  the  horny  hardness  like 
the  fibrous  system,  but  furnish  infinitely  less  gelatine  ; 
they  do  not  become  yellow  like  it.  The  pleura  in  those 
portions  of  the  thorax  of  animals  that  are  brought  to  our 
tables,  has  almost  its  ordinary  appearance  ; only  it  is  less 
shining,  has  lost  the  faculty  of  crisping  from  the  action 
of  caloric,  is  no  longer  affected  in  the  same  way  by  acids, 
&c.  If  it  was  of  a fibrous  nature  it  would  have  disap- 
peared in  gelatine,  on  account  of  its  delicacy.  I shall 
sa}'’  the  same  of  the  external  membrane  of  the  spleen,  the 
liver  and  the  lungs.  Compare  these  membranes,  that  are 
brought  to  our  tables,  when  boiled  with  the  intermuscu- 
lar aponeuroses,  the  tendons,  &c.  you  will  see  that  it  is 
impossible  to  confound,  as  has  been  done,  all  the  white 
textures  together,  in  regard  to  their  nature. 

If  we  compare  the  different  effects  of  agents  the  most 
known  upon  the  serous  system,  with  those  that  we  have 
observed  upon  the  cellular  system,  we  shall  see  that  they 
are  entirely  the  same  ; that  these  two  systems  are  con- 
sequently analogous,  and  even  identical. 

The  serous  system  when  it  putrefies  in  the  open  air 
does  not  become  green  like  the  skin,  but  is  of  a dull  and 
very  deep  grey.  During  life,  on  the  contrary,  its  black- 
ness is  very  evident  in  gangrene  which  is  sometimes  the 
result  of  an  acute  inflammation,  sometimes  of  those  chro- 
nic inflammations,  attended  with  many  small  white  tuber- 
cles, which  are  so  frequently  found  upon  these  membranes. 


14§ 


SEROUS  SYSTEM. 


This  difference  arises  from  the  circumstance,  that  in  the 
dead  body  these  surfaces  are  not  penetrated  with  blood  at 
the  time  they  become  putrid  ; whereas  they  contain  much 
during  life,  when  putrefaction  succeeds  inflammation  which 
has  filled  the  exhalants  with  it.  Many  other  facts  prove, 
that  the  greater  the  quantity  of  blood  there  is  in  a part 
when  it  putrefies,  the  more  livid  and  black  it  becomes. 
In  the  many  dead  bodies  that  I have  opened,  I have  never 
yet  observed  gangrene  except  in  the  peritoneum.  I have 
never  seen  it  in  the  pleura,  the  arachnoides,  the  pericar- 
dium, the  tunica  vaginalis ; it  no  doubt  takes  place  in 
them  ; but  I think  I have  opened  dead  bodies  enough 
to  allow  my  observation  to  establish  as  a general  princi- 
plej  that  the  peritoneum  is  more  subject  to  it  than  all  the 
other  analogous  organs. 

Though  the  different  considerations  offered  above  estab- 
lish much  analogy  between  the  cellular  and  the  serous 
systems,  they  exhibit  however  real  differences.  First 
their  external  appearance  is  not  the  same.  Then  there  is 
something  in  their  intimate  nature  that  we  are  unacquaint- 
ed with,  and  which  differs  also;  for  whenever  two  organs 
are  identical  in  their  nature,  they  are  subject  to  the  same 
affections ; now  there  is  a disease  of  the  serous  surfaces 
that  is  not  seen  in  the  cellular  system ; it  is  those  slow 
inflammations  of  which  I spoke  just  now,  a disease  wdiich 
should  not  be  ranked  in  the  class  of  the  fjhlegmasiae,  and 
which  the  production  of  the  small  tubercles  that  attend 
it,  especially  characterizes.  Authors  who  have  not  suf- 
ficiently attended  to  it,  have  denominated  it  chronic- 
enteritis  in  the  peritoneum,  latent  inflammation  in  the 
pleura,  &c.  though  however  foreign  to  every  subjacent 
organ,  except  in  the  latter  periods  when  it  is  propagated 
by  the  cellular  texture,  it  has  its  seat  exclusively  in  the 
serous  membranes,  and  is  an  affection  peculiar  to  these 
membranes,  as  miliary  eruptions  are  to  the  cutaneous 
surfaces,  as  qphlhse  to  the  mucous  surfaces,  &c.  Add 


SEROUS  SYSTEM. 


149 


to  this  difference  that  of  the  pus  which  the  cellular  tex- 
ture and  the  serous  surfaces  secrete ; this  fluid  is  not  the 
same  in  the  two  systems.  The  difference  of  its  nature  is 
not  known ; but  its  external  appearance  is  by  no  means 
the  same. 


II.  Parts  common  to  the  Organization  of  the  Serous 
System.  Exhalants. 

A very  evident  exhalation  is  constantly  going  on  upon 
the  serous  surfaces.  A particular  order  of  vessels  is  the 
agent  of  this  exhalation,  the  matter  of  which  is  the  fluid 
mentioned  above.  These  vessels  are  very  distinctly  de- 
monstrated in  this  system ; it  is  the  only  one  in  which 
the  eye  of  the  anatomist  can  accurately  trace  them.  The 
following  are  the  means  of  seeing  them  ; 1st,  in  a living 
animal,  draw  out  an  intestine  from  the  abdomen ; it  will 
have  a reddish  tinge  owing  to  the  vessels  under  the  serous 
coat,  and  hardly  at  all  to  the  vessels  in  this  coat  itself. 
Irritate  it,  and  reduce  the  intestine  after  attaching  a 
string  to  it,  as  in  the  operation  of  hernia  where  there  is 
gangrene,  draw  it  out  again  at  the  end  of  six  and  thirty 
or  eight  and  forty  hours  ; it  will  exhibit  many  reddish 
lines,  running  over  this  serous  surface,  and  showing  in  it 
plainly  the  exhalants  which  were  insensible  in  the  natural 
state,  on  account  of  the  transparency  of  their  fluids.  2d. 
Very  fine  injections  cover  in  an  instant  all  the  serous  sur- 
faces with  an  infinite  number  of  lines  of  the  colour  of  the 
injected  fluid,  lines  which  are  evidently  exhalants  full  of 
this  fluid.  3d.  In  these  injections  an  extremely  fine  dew  is 
made  to  ooze  out  upon  the  smooth  surface  of  the  serous 
membranes,  a dew  which  takes  place  without  rupture  or 
transudation,  and  of  which  the  exhalants  are  the  sources. 
4th.  If  a serous  surface  is  laid  bai’e  in  a living  animal, 
and  wiped  dry,  it  is  soon  after  covered  with  new  serum, 
which  the  exhalants  furnish. 


150 


SEROUS  SYSTEM, 


Absorbents. 

From  the  texture  of  the  serous  membranes,  it  is  evident 
that  the  lymphatic  system  enters  essentially  into  their 
formation,  and  that  they  are  probably  only  a net-work  of 
exhalants  and  absorbents  ; for  we  have  seen  that  the  cellu- 
lar organ  is  an  assemblage  of  them.  But  this  assertion 
which  analogy  dictates  is  also  supported  by  direct  proofs. 
1st.  The  fluid  of  the  dropsies  of  the  difierent  cavities 
varies  in  density  and  colour ; now  Mascagni  has  always 
observed  that  the  lymphatics  in  their  neighbourhood  con- 
tained a fluid  exactly  analogous.  2d.  The  same  author 
has  found  in  two  dead  bodies,  with  a sanguineous  effusion 
in  the  thorax,  the  absorbents  of  the  lungs  loaded  with 
blood.  3d.  In  a man  who  had  become  emphysematous 
after  having  been  poisoned,  these  vessels  were  distended 
with  air.  4th.  Coloured  fluids  injected  into  the  abdomen 
or  thorax  are  soon  after  found,  it  is  said,  in  the  neigh- 
bouring lymphatics,  with  the  same  colour.  I have  often 
repeated  this  experiment ; the  injected  fluid  has  been 
soon  absorbed,  but  not  the  matter  which  coloured  it ; so 
that  this  matter,  more  condensed  after  absorption,  tinged 
the  serous  surface,  the  lymphatics  being  as  transparent  as 
usual.  It  is  necessary  in  general  to  choose  the  abdomen 
for  these  experiments,  because  the  absorbents  being  much 
exposed  on  the  liver,  can  be  more  easily  examined  there. 
This  absorbent  faculty  is  preserved  some  time  after  death  ; 
but  care  should  be  taken,  in  order  to  obtain  then  the 
effect  more  certainly,  to  keep  the  animal,  if  a warm  blood- 
ed one,  in  a bath  of  nearly  its  own  temperature ; I have 
had  frequent  opportunities  of  being  convinced  of  this 
truth,  and  of  observing  with  Cruickshank,  that  what  Mas- 
cagni has  said  upon  the  absorption  of  dead  human  bodies, 
fifteen,  thirty,  fort5'^-eight  hours  even  after  death,  is  at 
least  very  much  exaggerated.  5th.  The  following  experi- 
ment I make  overy  year  to  demonstrate  the  absorbents  ; 


SEROUS  SYSTEM. 


151 


I macerate  for  five  or  six  hours  the  heart  of  an  ox  in 
water ; at  the  end  of  this  time,  the  serous  membrane  of 
this  organ,  which  hardly  allowed  these  vessels  to  be  per- 
ceived, appears  to  be  covei'ed  with  them,  6th.  When 
the  serous  membranes  are  inflamed,  the  subjacent  lym- 
phatics are  distended,  like  them,  by  the  red  globules  of 
blood,  &c.  &c. 

It  appears  then  to  be  demonstrated,  1st,  that  the  absor- 
bents open  by  an  infinite  number  of  orifices  upon  the 
serous  membranes  ; 2d,  that  their  origins  a thousand  times 
intermixed  with  each  other,  and  with  the  orifices  of  the 
exhalants,  contribute  especially  to  form  their  texture ; 
3d,  that  the  difficulty  of  distinguishing  the  absorbent 
and  exhalant  pores  is  no  reason  for  denying  their  exist- 
ence, this  difficulty  arising  from  their  extreme  delicacy 
and  from  the  oblique  direction  in  which  they  open  be- 
tween the  layers  of  these  membranes  ; thus  the  obliquity 
of  the  insertion  of  the  duct  of  Warton,  and  of  the  ductus 
choledochus  even  would  render  the  inspection  of  them 
very  difficult,  though  these  ducts  were  infinitely  larger  ; 
4th,  that  from  this  structure,  the  serous  membranes,  al- 
ways arranged  as  we  have  seen  in  the  form  of  sacs  with- 
out an  opening,  should  be  regarded  as  great  reservoirs 
between  the  exhalant  and  absorbent  systems,  in  which  the 
lymph  in  going  from  one  remains  some  time  before  enter- 
ing the  other,  in  which  it  undoubtedly  undergoes  various 
preparations  of  which  we  shall  always  be  ignorant,  be- 
cause it  would  be  necessary  to  analyze  it  comparatively 
in  these  two  orders  of  vessels,  which  is  almost  impossible, 
at  least  for  the  first,  and  finally  in  which  it  serves  dif- 
ferent uses  relative  to  the  organs  around  which  it  forms 
a humid  atmosphere. 

Blood  Vessels. 

Do  blood  vessels  enter  into  the  structure  of  the  serous 
membranes  ? These  vessels  are  very  numerous  around 


152 


SEROUS  SYSTEM. 


them,  as  is  seen  in  the  peritoneum,  the  pericardium,  the 
pleura,  &c. ; they  wind  upon  their  external  surface  and 
ramify  there.  But  I have  always  doubted  whether  the 
greatest  number  of  those  which  are  thus  contiguous  to 
them,  really  make  a part  of  their  texture,  and  I am  even 
convinced  of  the  contrary.  The  following  considerations 
support  my  opinion.  1st.  When  these  vessels  are  inject- 
ed, they  can  be  easily  raised  with  a scalpel  from  the  exter- 
nal face  of  these  membranes,  without  injuring  their  con- 
tinuity, which  can  never  be  done  in  the  fibrous  or  mucous 
membranes.  2d.  No  blood  vessel  is  discoverable  on  these 
membranes  which  are  free  on  both  faces.  The  arach- 
noides  at  the  base  of  the  cranium  furnishes  an  example  of 
this.  3d.  The  vessels  frequently  change  relations  with 
these  membranes.  I have  proved  above  that  when  the 
omentum  is  applied  to  the  stomach  when  it  is  full,  the 
vessels  that  are  between  its  layers,  do  not  mount  with  it 
upon  this  viscus,  on  account  of  the  great  stomachic  coro- 
nary which  opposes  it.  When  dead  bodies  having  large 
hernias  are  injected,  the  vessels  that  wind  in  the  ordi- 
nary state  upon  the  surface  of  the  peritoneum  which 
corresponds  to  the  ring,  are  not  seen  extending  below 
upon  the  hernial  sac.  Certainly  the  vessels  that  are 
observed  in  the  broad  ligaments  of  the  womb,  do  not 
follow  them  in  the  great  displacements  they  undergo  in 
pregnancy. 

I think  it  then  very  probable  that  the  serous  membranes 
have  but  very  few  blood  vessels  ; what  are  called  arteries 
of  the  peritoneum,  the  pleura,  &c.  are  but  trunks  wind- 
ing on  their  external  surface,  capable  of  abandoning  it 
when  they  are  displaced,  being  as  it  were  foreign  to  them, 
not  entering  immediately  into  their  structure,  to  which 
the  absorbent,  exhalant  and  cellular  systems  almost  alone 
contribute.  No  doubt  communications  exist  between  the 
arterial  system  and  the  serous  membranes,  by  means  of 
the  exhalants  ; but  nothing  precise  is  yet  known  upon  the 


SEROUS  SYSTEM. 


153 


nature,  arrangement,  and  to  a certain  extent  even,  the 
functions  of  these  vessels. 

III.  Varieties  of  Organization  of  the  Serous  System. 

We  have  seen  the  mucous  system  exhibiting  in  each 
part  where  it  is  found,  numerous  differences  of  structure 
and  varying  in  each  region  and  in  each  organ.  The  sex’ous 
system  varies  also,  though  less  than  the  preceding.  1st. 
Each  membrane  has  its  peculiar  structure.  Compare  for 
example,  the  arachnoides  and  the  peritoneum ; the  one 
fine,  delicate  and  transparent,  yields  to  the  least  effort, 
has  no  resistance,  tears  almost  as  soon  as  it  is  touched, 
never  remains  whole  at  the  base  of  the  cranium,  where 
it  is  free,  if  the  brain  is  raised  ever  so  little,  and  has, 
when  pressed  between  the  fingers,  a remarkable  softness. 
The  other,  thicker  and  more  compact,  bears  without 
breaking  all  the  efforts  imparted  to  the  abdominal  viscera ; 
it  can  be  pulled  with  impunity.  Its  texture  is  wholly 
different.  2d.  The  different  portions  of  the  serous  mem- 
branes have  not  the  same  organization  ; the  omentum  is 
for  example  evidently  dependant  upon  the  peritoneum 
and  yet  it  does  not  resemble  it.  I have  observed  that  the 
intestinal  portion  of  this  membrane  is  much  more  delicate 
than  its  hepatic,  mesenteric  portions,  &c.  That  the  half 
of  the  tunica  vaginalis  which  lines  the  albuginea  and  is 
identified  with  it,  is  certainly  not  the  same  as  the  half 
which  is  free  on  the  side  of  the  dartos  muscle.  I can- 
not say  precisely  in  what  these  differences  consist ; but 
the  external  appearance  is  sufficient  to  establish  them. 

Ought  we  then  to  be  surprised,  if  all  the  serous  sur- 
faces are  not  equally  subject  to  the  same  diseases ; if 
inflammation  attacks  them  with  such  different  degrees  of 
violence  ; if  it  takes  place  ten  times  upon  the  pleura  to 
once  that  it  appears  upon  the  arachnoides  ; if  in  the  peri- 
cardium, the  tunica  vaginalis  and  the  peritoneum,  it  does 
VOL.  III.  20 


154 


SEROUS  SYSTEM. 


not  exhibit  the  same  symptoms ; if  dropsies  vary  also 
wonderfully  in  each  ; if  the  slow  inflammations  attack 
them  differently,  &c.  ? The  pericardium  is  subject  to  an 
affection  which  I have  seen  upon  no  other  serous  surface, 
and  which  is  yet  extremely  frequent  upon  this ; I refer 
to  the  wl'iite  layers,  more  or  less  broad,  that  are  formed 
on  its  internal  surface,  which  would  be  thought  at  first 
view  to  belong  to  its  texture,  which  can  however  be 
raised  from  it  leaving  it  sound.  I do  not  know  whence 
these  layers  come  ; do  they  correspond  to  the  false  mem- 
branes of  the  pleura  ? 

Neither  should  we  be  surprised  at  what  has  been  said 
of  the  varieties  which  the  same  membrane  exhibits  in  its 
diseases.  Frequently  the  whole  of  the  peritoneum  is  dis- 
eased, and  the  omentum  remains  sound  and  vice  versa. 
The  layers  of  which  t have  just  spoken  are  seen  uporj  the 
cardiac  portion,  and  not  upon  the  free  portion  of  the  peri- 
cardium. 

Observe  however  that  all  the  diseases  of  this  system 
have  a common  character  which  is  evidently  derived  from 
the  analogy  of  organization.  This  and  the  synovial  are 
the  only  ones  in  which  large  serous  collections  take  place, 
in  which  slow  and  tubercular  inflammations  are  formed. 
The  most  of  their  modes  of  adhesion  belong  only  to  the 
serous  system.  Inflammation  has  a peculiar  and  distinc- 
tive character  in  it,  of  which  all  the  serous  membranes 
partake  with  some  modifications.  The  inflammation  of 
the  meninges  had  been  classed  among  the  serous  phleg- 
masias,  from  the  analogy  of  the  symptoms,  before  I had 
demonstrated  that  the  arachnoides,  one  of  these  meninges, 
belongs  essentially  to  the  serous  system.  It  is  on  account 
of  this  membrane,  and  not  on  account  of  the  dura-mater 
which  is  of  a fibrous  nature,  that  phrenitis  should  be 
referred  to  the  diaphanous  membranes. 


SEROUS  -SYSTEM. 


i5o 


ARTICLE  THIRD. 


PROPERTIES  OF  THE  SEROUS  SYSTEM. 


I.  Properties  of  Texture.  Extensibility. 

The  serous  membranes  are  endowed  with  an  exten- 
sibility much  more  limited,  than  the  enormous  dilatations 
of  which  they  are  capable  in  certain  cases,  would  at 
first  lead  us  to  believe.  The  mechanism  of  their  dilata- 
tion evidently  proves  it.  This  mechanism  depends  upon 
three  principal  causes  ; 1st,  upon  the  development  of  the 
folds  that  they  form,  and  this  is  the  most  powerful  of  the 
three  causes.  Hence  why  the  peritoneum,  which  of  all 
the  membranes  of  this  class,  is  the  most  exposed  to  dila- 
tations, as  from  pregnancy,  ascites  and  visceral  enlarge- 
ments, more  frequent  there  than  elsewhere ; hence,  I say, 
why  the  peritoneum  exhibits  so  great  a number  of  these 
folds,  such  as  the  mesentery,  the  mesocolon,  the  meso- 
rectum,  the  two  omen  turns,  the  fatty  appendices,  the  fold 
of  the  csecal  appendix,  the  broad  ligaments  of  the  womb, 
the  posterior  ones  of  the  bladder,  &c.  &c.  Hence  why 
also  these  folds  are  seen  around  organs  subject  to  habitual 
alternations  of  dilatation  and  contraction,  as  around  the 
stomach,  the  intestines,  the  womb  and  the  bladder ; very 
evident  in  the  second  state,  hut  slightly  apparent  in  the 
first.  2d.  The  enlargement  of  the  serous  cavities  belongs 
to  the  displacements  of  which  their  membranes  are  capa- 
ble. Thus  when  the  liver  is  considerably  enlarged,  its 
serous  membrane  increases  its  extent  in  part  at  the  ex- 
pense of  that  of  the  diaphragm,  which  being  drawn  is 


156 


.SEROUS  SYSTEM. 


detached  andr-applied  upon  the  enlarged  viscus.  I have 
seen,  in  an  aneurism  of  the  heart,  the  pericardium  which 
had  been  able  to  yield  but  very  little,  detached  in  part 
from  the  portion  of  the  great  vessels  which  it  covered. 
3d.  Finally,  the  texture  of  these  membranes  undergoes  a 
real  distension  and  elongation.  But  it  is  in  general  the 
least  sensible  cause  of  the  enlargement  of  their  cavity ; ^ 
it  is  only  in  the  great  enlargements  that  it  has  an  evident 
influence  ; in  common  cases,  the  two  first  causes  are  almost 
always  sufficient. 

I will  make  an  important  remark  upon  the  subject  of 
the  displacements  of  which  the  serous  membranes  are  the 
seat  in  the  motions  of  their  respective  organs ; it  is  that 
these  displacements  are  very  painful  when  these  mem- 
branes are  inflamed.  When  the  dilated  intestines  separate 
the  two  diseased  layers  of  the  mesentery  to  lie  between 
them,  when  the  stomach  goes  between  those  of  the  omen- 
tum, &c.  when  the  peritoneum  is  inflamed,  the  patient 
suffers  much.  Hence  why  flatulence  is  then  so  painful, 
why  it  is  then  necessary  to  avoid  taking  at  once  a great 
quantity  of  drink.  We  know  the  acute  pain  that  a long 
inspiration  produces  in  pleurisy ; it  is  because  the  lungs 
then  dilate  the  pleura,  and  tend  to  go  between  the  folds 
which  accompany  the  great  pulmonary  vessels. 

Contractility. 

It  corresponds  with  the  extensibility ; it  is  less  con- 
sequently than  it  at  first  appears  to  be.  When  the  pei’i- 
toneum  for  example  is  contracted,  its  different  folds  are 
formed  ; it  returns  to  its  place  after  having  experienced 
locomotions.  But  it  cannot  be  denied  that  in  great  dilata- 
tions these  two  properties  are  very  sensible  ; for  example, 
in  hydrocele  as  the  water  is  evacuated,  the  tunica  vagi- 
nalis evidently  contracts.  The  peritoneum  after  the  para- 
centesis of  the  abdomen  exhibits  the  same  phenomenon. 


SEROUS  SYSTEM. 


157 


At  the  time  of  performing  the  operation  of  empyema, 
the  pleura  does  not  experience  it  so  sensibly,  not  from 
defect  of  contractility,  but  because  on  the  one  hand  it 
adheres  to  the  ribs  which  do  not  contract,  and  on  the 
other  if  the  effusion  is  of  long  standing,  the  lungs  are  so 
flattened  by  the  pressure,  that  the  air  can  no  longer  dilate 
them,  so  that  there  remains  a space  between  the  costal 
and  pulmonary  portion,  which  is  filled  with  air.  A simi- 
lar space  would  also  remain  at  the  moment  of  the  opera- 
tion, if  the  serum  of  hydrocephalus  was  evacuated. 

After  long  distensions,  the  serous  membranes  no  longdl' 
contract;  the  tunica  vaginalis  remains  flaccid  after  fre- 
quent punctures,  the  peritoneum  after  frequent  preg- 
nancies, &c.  &c. 


II.  Vital  Properties. 

The  serous  surfaces,  being  removed  from  the  action  of 
external  bodies,  do  not  enjoy  in  the  natural  state  the  pro- 
perties which  put  the  living  organs  in  relation  with  exter- 
nal bodies ; they  have  neither  animal  sensibility  nor  con- 
tractility. Thus  they  would  be  very  improper  for  exter- 
nal integuments,  or  for  linings  of  the  organs  which  the 
mucous  membranes  cover;  they  would  give  in  fact  no 
other  sensation  than  that  of  an  obscure  and  indistinct 
feeling.  They  answer  very  well  for  envelopes,  integu- 
ments for  internal  organs,  but  not  for  sensible  envelopes. 
We  have  a proof  of  it  in  living  animals  in  whom  we  can 
irritate  these  membranes  with  impunity.  I have  many 
times  seen  dogs  in  whom  I had  left  the  spleen  drawn  out 
of  the  abdomen,  in  order  to  observe  the  phenomena  arising 
from  it,  tear  this  organ  without  being  in  a state  of  fury, 
eat  it  even  and  be  thus  nourished  by  their  own  substance. 
They  also  often  tear  without  pain  the  exterior  of  their 
intestines  when  in  experiments  these  are  drawn  out,  and 
the  animals  are  left  some  time  to  themselves. 


158 


'SEROUS  SYSTEM, 


When  external  bodies  are  in  contact  with  the  serous 
system,  they  change  its  natural  state  ; they  inflame  it,  as 
we  see  in  the  peritoneum,  in  the  tunica  vaginalis  laid 
• bare,  as  we  observe  also  always  when  a foreign  body  in-' 
.troduced  into  the  system  acts  upon  them.  Surgeons,  as 
we  know,  even  employ  this  means  to  which  they  would 
in  vain  have  recourse  in  the  mucous  membranes,  in  order 
to  procure  artificial  adhesions  between  the  parietes  of 
these  membranes.  The  different  morbid  irritations  in- 
flame much  more  frequently  the  serous  surfaces  which 
in  this  state  acquire  a very  acute  sensibility,  greater  even 
than  that  of  the  integuments  ; so  that  these  inflamed 
surfaces  -svould  be  equally  improper  to  serve  for  integu- 
ments, because  external  bodies  would  excite  them  pain- 
fully. , . . 

The  sensible  organic  contractility  is  nothing  in  the 
serous  system  ; but  the  insensible  and  the  corresponding 
sensibility  are  kept  in  permanent  exercise  in  it,  1st,  by 
the  continual  exhalation  and  absorption  that  are  going  on 
there ; 2d,  by  nutrition.  These  two  properties  are  then 
those  which  predominate  in  this  system  ; thus  upon  their 
alterations  all  its  diseases  turn.  Acute  inflammations, 
chronic  inflammations  with  tubercles,  adhesions,  dropsies, 
exhalations  of  pus,  of  milky  serum,  &c.  &c.  are  all  de- 
rived from  an  excess,  a defect  or  an  alteration  of  these 
two  properties  of  the  serous  system.  It  is  then  also  almost 
exclusively  that  sympathies  are  put  into  action  in  it ; so 
that  the  serous  membranes  diseased  either  idiopathically 
or  sympathetically  exhibit  always  a series  of  phenomena 
all  of  which  suppose  an  increased  internal  motion,  or  loss 
of  tone  in  the  exhalant  and  absorbent  capillaries,  and  in  the 
peculiar  texture  of  those  membranes  ; whilst  in  the  animal 
muscular,  the  organic  muscular  systems,  &c.  these  pre- 
dominant affections  which  arc  marked  by  convulsions  and 
paralysis  in  one,  and  by  irregular  motions  of  irritability 
in  the  other,  do  not  suppose  this  internal  alteration  of  the 


SEROUS  SYSTEM. 


159 


texture  of  the  diseased  organ.  Hence  why  these  two  last 
systems,  though  frequently  disturbed  during  life,  exhibi 
but  few  changes  after  death,  whilst  the  serous  system  is 
a vast  field  for  the  morbid  anatomist. 


Sympathies. 

The  serous  surfaces  are  capable  of  being  influenced  by 
the  afiections  of  the  other  organs  ; this  is  very  evident  in 
the  organic  diseases  of  the  heart,  the  lungs,  the  liver,  the 
spleen,  the  stomach,  the  womb,  &c.  organs,  which  with- 
out having  any  known  connexion  of  functions  with  the 
serous  surfaces,  influence  them  however  so  that  all  their 
morbid  defects  of  organization  are  accompanied,  in  the 
latter  periods,  by  different  serous  collections  in  the  great 
cavities,  colle'ctions  evidently  owing  to  a derangement  of 
the  organs  which  constantly  exhale  this  fluid.  I shall 
make  upon  this  point  two  observations  ; the  first  is  that 
the  serous  surfaces  nearest  the  diseased  organ,  are  in 
general  the  most  susceptible  of  being  influenced  by  it. 
Thus  in  the  diseases  of  the  heart  and  the  lungs,  the  serous 
collections  take  place  especially  in  the  thorax,  whilst  as- 
cites is  always  the  first  consequence  of  enlargements  of 
the  liver,  the  spleen,  &c.  the  pleura  and  the  pericardium 
being  filled  subsequently.  We  know  that  most  sarcoceles 
are  complicated  with  dropsies  of  the  tunica  vaginalis; 
whence  results  hydro-sarcocele,  a disease  which  surgeons 
consider  separately,  but  which  is  the  same  as  those  of  the 
preceding  cases,  which  might  in  this  respect  be  called 
hydro'-phthisis,  chronic  hydro-hepatitis,  hydro-carcinoma 
of  the  womb,  &c. 

The  second  observation  that  I have  to  make  is,  that 
whenever  the  serum  is  thus  collected  in  the  cavities,  in 
consequence  of  an  organic  disease  of  a viscus  foreign  to 
the  membrane,  this  serum  is  limpid,  transparent,  and 
probably  of  the  same  nature  as  that  which  circulates  in 


160 


SEROUS  SYSTEM. 


the  lymphatic  vessels.  The  exhalants  which  form  it  not 
being  then  in  fact  diseased,  their  action  not  being  increas- 
ed or  that  of  the  absorbents  diminished  except  by  sym 
pathy,  the  fluid  must  remain  the  same.  Thus  though  there 
is  suflei’ing  at  the  end  of  the  glans  from  a stone  in  the 
bladder,  the  glans  is  perfectly  sound,  and  the  mucous 
fluid  that  escapes  from  it  is  of  the  same  nature  as  in  the 
ordinary  state.  On  the  contrary,  when  dropsies  depend 
upon  a disease  of  texture  of  the  serous  surfaces,  as  for  ex- 
ample upon  a tubercular  inflammation,  or  even  an  acute 
one,  which  has  degenerated,  &c.  the  effused  serum  is 
almost  always  altered;  it  is  milky,  or  there  are  albumi- 
nous flakes  in  it,  or  a false  membrane,  &c.  I have  made 
this  observation,  which  I think  interesting,  upon  nearly 
all  the  bodies  I have  opened. 

In  acute  diseases,  the  serous  surfaces  receive  also  equally 
the  sympathetic  influence  of  the  afiected  organs.  If  we 
could  then  see  them,  we  should  find  that  they  were  like 
the  skin,  more  or  less  moist,  more  or  less  dry,  according 
to  the  different  periods  of  tlie  disease.  What  proves  it 
is,  that  at  the  death  which  follows  the  disease,  the  serum 
of  the  pleura,  the  pericardium,  the  peritoneum,  &c.  varies 
remarkably.  Sometimes  it  is  evidently  increased,  at 
others  it  is  almost  nothing ; this  depends  upon  the  time 
in  which  the  subject  died.  If  it  is  whilst  exhalation  is 
very  abundant,  we  find  much  serum ; it  is  almost  nothing 
if  life  has  been  sufficiently  prolonged  to  allow  absorption 
to  take  place.  If  the  surrounding  air  did  not  dissolve 
the  sweat,  or  if  the  skin  was  in  the  form  of  a sac,  we 
should  find  it  with  very  variable  degrees  of  moisture, 
according  as  the  subjects  had  died  in  sweat,  or  with  a 
xuppression  of  the  cutaneous  exhalation. 


SEROUS  SYSTEM. 


161 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  SEROUS  SYSTEM. 


I.  State  of  this  System  in  the  First  Jige. 

■All  the  serous  surfaces  are  extremely  delicate  in  the 
foetus.  In  opening  the  thorax  by  a longitudinal  section 
of  the  sternum  and  examining  the  pleura  in  the  medias- 
tinum where  it  is  free  on  both  sides,  it  is  found  to  have  less 
thickness  than  the  transparent  layers  of  the  omentum  or 
the  arachnoides  in  the  adult.  The  peritoneum  is  a little 
thicker  in  proportion,  but  yet  its  delicacy  is  very  great. 
The  comparison  of  soap  bubbles  is  hardly  sulEcient  to 
convey  an  idea  of  the  fineness  of  the  texture  of  the 
omentum  and  the  arachnoides. 

At  this  period  the  fluid  that  lubricates  the  serous  sur- 
faces is  much  more  unctuous  and  viscid  than  it  is  after- 
wards ; by  carrying  the  fingers  over  these  surfaces  at  the 
different  ages,  the  difference  is  easily  perceived.  It  might 
almost  be  said  that  the  tangible  qualities  of  the  serous 
fluids  then  approximate  those  of  the  synovia.  I know 
not  to  what  this  difference  belongs. 

Besides,  the  quantity  of  these  fluids  does  not  appear  to 
be  so  great  in  proportion  as  that  of  the  cellular  fluids, 
with  which  they  have  however  so  much  analogy  ; which 
is  probably  owing  to  this,  that  the  internal  motions  being 
less  numerous,  on  account  of  the  inaction  of  most  of  the 
organic  muscles,  less  fluid  is  necessary  to  lubricate  the 
surfaces. 

The  growth  of  the  serous  system  is  always  in  propor- 
tion to  that  of  the  organs  which  it  covers.  The  arach- 
VOL.  III.  21 


162 


SEROUS  SYSTEM. 


noides  is  larger  in  proportion  than  it  will  be  in  the  adult ; 
it  seems  even,  like  the  brain,  to  become  then  the  seat  of 
a more  active  labour  ; thus  diseases  are  more  frequent  in 
it.  The  increase  of  exhalation  is  more  common  in  it 
than  in  all  the  other  serous  sacs  ; hence  hydrocephalus. 

At  birth,  when  the  internal  motions  become  suddenly 
vei’)^  numerous,  on  account  of  respiration,  digestion  and 
the  excretions,  I presume  that  the  serous  surfaces  become 
tlie  seat  of  a more  active  exhalation.  Besides,  as  very 
little  blood  penetrates  them,  the  sudden  production  of  the 
red  blood  and  its  entrance  by  the  arterial  system,  whetb  it 
succeeds  the  black  blood,  produces  less  changes  upon  them 
than  upon  the  mucous  surfaces  and  the  muscular  system. 

The  serous  membranes  grow  like  the  other  organs ; 
for  a long  time  delicate  and  diaphanous,  they  gradually 
thicken  as  we  advance  in  age,  and  become  of  a dull  white. 
Their  suppleness  diminishes  as  their  density  increases  ; 
they  resist  the  different  reagents  so  much  the  less  as  the 
subjects  are  younger.  In  infants,  maceration  and  ebullition 
reduce  them  much  more  quickly  to  a homogeneous  pulp. 

I have  observed  that  in  the  foetus  which  has  become 
putrid,  there  is  often  collected  different  gases  in  the  serous 
cavities,  as  may  be  proved  by  opening  these  cavities  under 
water  ; a phenomenon  much  less  evident  in  the  adult, 
in  whom  the  cellular  texture  is  often  wholly  emphyse- 
matous by  the  putrefactive  motion,  without  the  escape 
of  any  thing  by  the  canula  of  a trochar  which  is  plunged 
into  the  peritoneal  cavity  or  into  that  of  the  pleura,  as  I 
have  many  times  ascertained.  In  general,  thers  is  dis- 
engag-ed  much  more  aeriform  fluid  from  the  organs  of  the 
fetus,  than  from  those  of  the  adult,  in  tire  experiments 
of  maceration. 

II.  Stat&  of  the  Serous  System  in  the  after  Ages. 

In  the  adult,  the  serous  system  remains  a long  time 
without  undergoing  any  very  sensible  change  ; its  mem- 


SEROUS  SYSTEM, 


163 


branes  follow  only  the  laws  of  the  organs  they  surround. 
Thus  in  the  age  nearest  youth,  the  serous  surfaces  of  the 
chest  are  the  most  frequent  seat  of  inflammations,  drop- 
sies, &c, ; whilst  in  that  bordering  on  old  age  the  inferior 
surfaces  like  the  peritoneum,  are  the  more  often  affected. 

In  old  age,  the  serous  system  becomes  dense  and  com- 
pact ; its  adhesions  to  the  neighbouring  parts  are  more 
evident ; thus  it  is  less  capable  of  the  different  locomo- 
tions of  which  we  have  spoken.  Its  forces,  which  are 
weakened,  render  absorption  in  it  less  easy  ; it  is  the  fre- 
quent seat  of  dropsy.  When  it  is  affected  with  some 
diseases,  its  want  of  energy  imparts  to  them  a remark- 
able chronic  character.  There  are  many  old  people  at 
the  Hotel  Dieu  with  tubercular  inflammations  of  the 
peritoneum,  which  they  have  had  for  a long  time,  whilst 
young  persons  are  overcome  much  quicker  by  the  same 
inflammations.  Thus  cancers  in  aged  persons  often  re- 
main almost  inert,  they  frequently  are  not  even  painful, 
whilst  their  periods  are  usually  most  rapid  in  adults. 

The  serous  effusions  are  more  rare  than  the  infiltrations 
of  the  sub-cutaneous  cellular  texture  in  old  people ; but 
they  take  place  more  commonly  than  those  of  the  inter- 
muscular texture. 

The  serous  system  becomes  ossified,  but  not  like  the 
arterial,  the  cartilaginous,  &c.  from  the  natural  effect  of 
age.  Its  membranes  are  not  constantly  found  osseous  in 
old  age,  and  when  this  phenomenon  takes  place,  it  hap- 
pens at  every  age.  It  is  a disease,  a real  tumour,  whilst 
in  the  arteries  and  the  cartilages  it  appears  to  belong  to 
a natural  series  of  functions.  I have  a preparation  in 
which  the  arachnoides  is  evidently  osseous  in  many  points, 
and  as  it  is  upon  the  dura-mater  that  these  productions 
are  formed,  their  existence  serves  very  well  to  prove  that 
the  arachnoides  is  distinct  from  it ; for  at  the  place 
where  they  are  found,  they  can  be  easily  separated  from 
each  other. 


164 


SEROUS  SYSTEM. 


III.  Preternatural  Development  of  the  Serous  System. 

I shall  not  repeat  here  what  I have  said,  in  speaking  of 
the  cellular  texture,  upon  the  formation  of  the  different 
cysts.  These  cysts,  completely  analogous  to  the  natural 
serous  membranes,  should  be  really  considered  as  a pre- 
ternatural development  of  these  membranes  in  the  econo- 
my ; they  have  the  same  appearance  and  almost  the  same 
texture,  furnish  their  fluid  according  to  the  same  laws, 
and  appear  to  be  the  seat  of  a constant  exhalation  and  ab- 
sorption ; since  they  are  in  vain  emptied  by  puncture, 
their  fluids  are  always  reproduced,  until  they  are  remov- 
ed. For  example  compare  the  cyst  which  has  grown 
preternaturally  along  the  spermatic  cord,  with  the  tunica 
vaginalis  filled  with  water  in  hydrocele.  If  the  size  of 
these  tumours,  which  are  often  found  together,  is  * the 
same,  it  is  impossible  to  discover  any  difference  in  their 
form,  appearance,  texture,  properties,  functions,  &c. 


SYNOVIAL  SYSTEM. 


I PLACE  this  system  at  the  side  of  the  serous,  be- 
cause it  has  the  greatest  analogy  with  it,  under  the  rela- 
tions, 1st,  of  its  form,  which  is  in  each  of  these  organs 
that  of  a sac  without  an  opening ; 2d,  of  its  texture,  which 
appears  to  be  essentially  cellular  ; 3d,  of  its  functions, 
which  consist  in  an  alternation  of  exhalation  and  absorp- 
tion. 

What  establishes  a real  line  of  demarcation  between 
these  two  systems  is,  1st,  that  the  fluids  which  lubricate 
their  membranes  appear  to  difler  in  their  composition, 
though  there  is  much  resemblance  between  them,  2d. 
In  dropsical  diatheses  which  afiect  at  the  same  time  the 
cellular  texture  and  all  the  serous  surfaces  of  the  peri- 
toneum, the  pleura,  &c.  the  affection  does  not  extend  to 
the  synovial  membranes,  which  indicates  a difference  of 
structure,  though  we  do  not  know  what  this  difference  is. 
3d.  And  reciprocally  in  dropsies  of  the  articulations,  an 
affection  in  general  very  rare,  and  in.  those  of  the  tendi- 
nous synovial  capsules,  there  is  no  concomitant  afiection  of 
the  membranes  of  the  great  cavities.  4th.  The  fluid  of 
the  articular  dropsies  does  not  resemble  that  which  fills 
the  great  cavities  in  the  same  disease.  5th.  The  synovial 
membranes  are  much  more  rarely  tli an  the  serous,  the 


166 


SYNOVIAL  SYSTEM. 


seat  of  tliose  slow  and  tubercular  inflammations  which  the 
serous  surfaces  so  often  exhibit.  I have  however  seen 
two  examples  of  it  in  the  synovial  membrane  of  the  knee. 
I believe  that  these  two  systems  are  the  only  ones  in 
which  this  disease  is  observed  ; so  that  it  is  by  its  exist- 
ence a character  of  resemblance,  and  by  its  rarity  or  fre- 
quency, a distinguishing  attribute.  6th.  The  different 
kinds  of  adhesions  of  which  I have  spoken  as  taking  place 
on  the  serous  surface,  are  not  met  with  on  the  synovial 
surfaces,  where  we  see  only  that  which  identifies  these 
two  adhering  surfaces,  a mode  which  frequently  takes 
place  in  anchylosis,  which  is  also  as  often  occasioned  by 
it,  as  by  the  stiffness  of  the  parts  surrounding  the  articu- 
lation. 7th.  The  synovial  surfaces  are  not  as  often  as  the 
serous,  the  seat  of  those  remarkable  locomotions  of  which 
we  have  spoken  ; which  depends  on  this,  that  the  articui- 
lar  organs  are  not,  like  the  most  of  those  covered  with 
serous  surfaces,  subject  to  alternate  dilatations  and  con- 
tractions. 

The  synovial  system  exhibits  evidently  two  great  divi- 
sions. To  one  belongs  the  articular  system,  to  the  other 
that  of  the  tendinous  grooves.  Each  shall  be  examined 
separately. 


ARTICLE  FIRST. 

ARTICULAR  SYNOVIAL  SYSTEM. 

I BELIEVE  that  I first  described  this  essential  portion  of 
the  synovial  system.  I shall  relate  here  what  I have  said 
of  it  elsewhere.  I shall  examine  first  how  it  is  separated 


SYNOVIAL  SYSTEM. 


167 


from  the  blood,  afterwards  the  fluid  itself,  and  then  1 shall 
describe  the  organ  which  furnishes  it. 

I.  How  the  Synovia  is  separated  from  the  mass  of 
Blood. 

Every  fluid  difiering  from  the  blood,  can  be  separated 
from  it  to  be  afterwards  transmitted  to  an  organ,  but  in 
one  of  the  three  following  ways  ; 1st,  by  secretion,  a func- 
tion characterized  by  the  existence  of  a gland  interme- 
diate to  the  blood  vessels  that  bring  the  materials  to  it, 
and  the  excretories  which  carry  OS'  the  result ; 2d,  by 
exhalation,  a function  distinguished  from  the  first,  by  the 
absence  of  this  intermediate  gland,  and  by  the  immediate 
continuity  of  the  blood  vessel  and  the  exhaling  duct ; 3d, 
by  transudation,  a phenomenon  purely  physical,  almost 
always  happening  after  death,  rarely  observed  during  life, 
a simple  transmission  of  a fluid  by  the  pores  of  an  organ, 
towards  which  it  is  mechanically  determined.  Let  us 
examine  which  of  these  three  modes  is  that  chosen  by 
nature  to  deposit  the  synovia  upon  the  articular  surfaces. 

Is  the  synovia  transmitted  by  secretion  to  the  articu- 
lar surfaces  ? 

We  are  indebted  to  Clop  ton  Havers  for  the  system 
which  places  in  the  glands  the  sources  of  the  synovia. 
Many  authors  had  designated  obscurely  before  him  these 
organs  in  the  articulations ; but  he  made  them  the  partL 
cular  object  of  his  researches,  described  them  in  the  dif- 
ferent articulations,  divided  them  into  two  classes,  the 
one  principal,  the  other  accessory,  and  assigned  them 
chai’acters  so  evident,  that  according  to  him,  they  could 
not  be  forgotten.  Reddish  bunches,  spongy,  formed  by 
membranes  folded  upon  themselves,  situated  sometimes 
without,  and  sometimes  within  the  articulations,  always 
arranged  so  as  to  be  protected  from  too  strong  a compres- 
sion, and  pouring  out  through  ducts  in  the  form  of  fringe 


168 


SYNOVIAL  SYSTEM. 


the  fluid  they  secrete  ; such  are  the  characters  drawn  by 
Havers,  which  all  anatomists  since  him  admire,  and  the 
correctness  of  which  the  most  modern  and  distinguished 
authors  have  acknowledged  in  their  works. 

Some  anatomists  of  this  age  have  however  thrown 
doubts  upon  these  glandular  bodies.  Lieutaud  confounds 
them  with  the  fatty  cellular  texture.  Desault  did  not 
distinguish  them  from  it.  Every  thing  confirms  me  in 
the  same  opinion,  which  many  considerations  appear  to 
establish  in  an  undoubted  manner.  The  following  are 
these  considerations ; 1st,  these  reddish  bunches  are  met 
with  only  in  certain  articulations.  There  are  many  of 
them  in  which  their  existence  cannot  be  established  but 
by  supposition.  2d.  The  greatest  number  of  the  synovial 
membranes  of  the  tendons  certainly  do  not  exhibit  any 
of  them,  though  Havers,  Albinus,  Juncke  and  Fourcroy 
admit  them  in  all,  founded  no  doubt  upon  analogy  and 
not  upon  inspection.  Yet  the  synovia  is  separated  equally 
in  both  cases,  and  lubricates  the  surfaces  of  the  articula- 
tions and  of  the  tendinous  sheaths  ; this  separation  is  then 
independent  of  glandular  action.  3d.  If  the  best  marked 
synovial  glands  are  examined,  such  as  that  of  the  cotyloid 
cavity,  no  trace  can  be  discovered  there  of  this  paren- 
chyma of  an  unknown  nature,  but  remarkable  for  its 
structure,  which  composes  in  general  the  glands,  and 
which  distinguishes  them  from  every  other  part  and  forms 
their  true  organic  character.  4th.  No  excretory  duct  can 
be  demonstrated  in  these  organs.  Those  in  the  form  of 
fringes,  admitted  by  Havers,  are  imaginary.  Bertin  him- 
self has  acknowledged  this  truth,  though  he  attributed  to 
these  bodies  a glandular  structure.  The  transudation  of 
the  fluids  injected  by  the  arteries  in  the  neighbourhood 
of  the  articulation,  proves  the  existence  of  these  ducts  no 
better  than  it  establishes  them  in  the  cavities  of  the 
serous  membranes  in  which  it  also  takes  place,  and  yet 
in  which  it  is  well  proved  that  no  gland  pours  out  the 


SYNOVIAL  SYSTEM. 


169 


albuminous  fluid  that  constantly  lubricates  these  cavities, 
ffth.  Inflation  resolves  completely  these  fatty  bunches  into 
cellular  texture.  Maceration  produces  the  same  effect. 
When  gradual  and  long  continued  ebullition  has  removed 
all  the  fat  from  them,  there  remains  only  a mass  of  cells 
pressed  together,’ and  similar  to  those  of  the  common 
cellular  texture.  6th.  The  glandular  character  is  mani- 
fested in  certain  morbid  cases,  by  a peculiar  swelling  and 
hardening,  of  which  the  other  organs  except  the  glands, 
such  as  the  muscles,  the  tendons,  &c.  never  offer  an  exam- 
ple. The  liver,  the  kidneys,  the  salivary  organs,  all  the 
considerable  glands  are  remarkable  for  this.  So  true  is  this 
character,  that  it  serves  to  indicate  glands,  the  delicacy 
of  which  conceals  them  in  the  natural  state.  For  exam- 
ple, the  existence  of  the  cryptee  of  the  stomach,  the 
urethra,  and  several  other  mucous  membranes,  is  founded 
first  upon  the  analogy  of  the  other  membranes  of  this 
class,  but  principally  upon  the  preternatural  development 
which  these  cryptae  acquire  in  certain  diseases.  Never 
on  the  contrary,  do  the  pretended  synovial  glands  pre- 
sent to  the  observer  a similar  development.  Always  in 
the  diseases  of  the  articulations,  a common  swelling  seems 
to  identify  them  with  the  neighbouring  cellular  texture. 
They  have  not  like  the  other  glands,  affections  distinct 
from  those  of  this  texture,  no  doubt  because  they  have 
not  a peculiar  vitality,  because  being  mere  elongations  of 
the  neighbouring  cellular  texture,  they  partake  of  its 
nature  and  properties,  and  ought  consequently  to  partake 
of  all  its  conditions,  as  it  in  its  turn  ought  immediately  to 
receive  the  influence  of  their  affections. 

The  considerations  which  I have  just  offered  succes- 
sively form,  I think,  sufficient  data  to  resolve  the  problem 
proposed  above,  by  establishing  as  an  incontestable  propo- 
sition, that  the  synovia  is  not  transmitted  by  secretion  to 
the  articular  surfaces. 


VOL.  III. 


22 


170 


SYNOVIAL  SYSTEM, 


Let  us  examine  the  second  mode  of  transmission  stated 
by  authors. 

Is  the  synovia  transmitted  by  transudation  to  the 
articvlar  surfaces  ? 

It  was  an  opinion  anciently  received,  that  the  marrow 
of  the  long  bones  oozes  through  the  pores  of  their  ex- 
tremities and  through  those  of  the  cartilages  which  termi- 
nate them,  to  lubricate  the  articular  surfaces.  Havers 
renewed  this  idea  forgotten  at  the  time  he  wrote,  united 
this  source  of  the  synovia  to  that  which  had  placed  it  in 
the  glands,  and  thus  formed  of  this  fluid  a mixture  com- 
posed of  two  fluids  difierently  transmitted  to  the  articula- 
tion. The  most  of  those  who  succeeded  him  partook  of 
his  opinion  upon  this  point.  Those  even,  such  as  De- 
sault, who  rejected  the  existence  of  the  articular  glands 
and  the  secretion  of  synovia,  admitted  the  transudation 
of  it  founded  upon  the  following  observations,  1st.  A 
long  bone,  stripped  of  its  soft  parts  and  exposed  to  the 
air,  allows  a fatty  oozing  to  pass  through  the  pores  of  its 
cartilage?  which  does  not  cease  till  the  medullary  juice  is 
completely  exhausted.  2d.  The  mechanical  compression 
of  the  cartilaginous  extremity  of  a long  bone  produces 
for  a moment  the  same  effect.  Are  these  facts,  which 
are  evident  in  the  dead  bone,  also  real  in  the  living  one  ? 
Different  considerations,  which  I will  now  state,  induce 
one  to  believe  the  contrary. 

1st.  The  vital  forces,  the  effect  of  which  is  to  impart 
to  all  the  organs  which  they  animate  a degree  of  tone 
sufficient  to  resist  the  entrance  of  the  fluids,  leave,  when 
they  are  extinct,  the  fibres  of  these  same  organs  in  a state 
of  laxity  that  renders  them  everywhere  permeable.  Thus 
transudation  is  now  considered  as  hardly  any  thing  else 
than  a phenomenon  that  takes  place  only  after  death, 
which,  if  transformed  into  a vital  one,  would  oflTer  an  evi- 
dent exception  to  the  laws  of  nature  that  are  especially 
characterized  by  simplicity  and  uniformity.  2d.  The 


SYNOVIAL  SYSTEM. 


171 


fatty  oozing  takes  place  in  the  experiment  noticed  above, 
not  only  through  the  pores  of  the  cartilages,  but  also 
through  those  of  the  whole  surface  of  the  bone  ; so  that 
by  reasoning  from  what  has  been  here  observed  upon  the 
dead  body,  it  is  evident  that  during  life  the  whole  bone 
would  be,  if  you  may  so  say,  immersed  in  an  atmosphere 
of  synovia,  a consequence,  which  being  proved  false 
by  the  most  simple  inspection,  demonstrates  the  falsity 
of  the  principle  deduced  from  it.  3d.  The  articulations 
of  the  cartilages  of  the  larynx  are  lubricated  like  those  of 
the  bones,  by  the  synovial  fluid  ; and  yet  here  all  transu- 
dation of  marrow  is  impossible,  as  it  does  not  exist  in  the 
substances  of  the  cartilages.  4th.  The  marrow  is  almost 
always  sound  in  diseases  which,  affecting  the  articulations 
alter  the  fluid  that  lubricates  them.  And  reciprocally  the 
synovia  does  not  take  a different  character  in  the  affections 
of  the  interior  of  the  bones,  which  have  an  influence 
especially  upon  the  medullary  organ.  5th.  Finally,  the 
experiment  that  I have  made,  and  which  has  been  stated 
in  the  article  upon  the  marrow,  evidently  proves  the 
non-transudation  of  this  fluid. 

Desault,  in  order  to  explain  the  manner  in  which  the 
synovia  is  separated  from  the  blood,  added  to  this  pre- 
tended transudation  of  the  marrow,  an  oozing  furnished 
by  all  the  parts  contained  in  the  articulation,  such  as  the 
capsular  and  inter-articular  ligaments,  the  internal  fat,  the 
cartilages,  &c.  A comparison  will  suffice  to  show  the 
value  of  this  hypothesis.  What  should  we  say  of  a sys- 
tem in  which  to  explain  the  production  of  the  serous  fluid 
of  the  abdomen,  the  source  of  it  should  be  placed  in  the 
liver,  the  spleen,  the  intestines,  and  in  general  in  all  the 
organs  of  this  cavity  ? No  doubt  we  should  answer, 
that  a fluid  of  the  same  nature,  could  not  be  furnished  by 
parts  of  such  different  structure,  that  it  is  much  more 
simple  to  search  for  a single  source  in  the  single  mem- 
brane that  covers  all  the  gastric  viscera.  The  application 


172 


SYNOVIAL  SYSTEM, 


is  exact  and  the  analogy  perfect  between  it  and  the  artic- 
ular cavit}^. 

We  can,  I believe,  without  fear  of  error,  conclude  from 
all  that  has  been  said  above,  that  the  synovia  is  not  trans- 
mitted by  transudation  to  the  articular  surfaces. 

I will  now  examine  the  last  mode  pointed  out  for  the 
separation  of^he  synovia. 

Is  the  synovia  transmitted  by  exhalation  to  the  ar- 
ticular surfaces  7 

The  solution  of  the  two  preceding  problems  seem  natu- 
rally to  lead  to  that  of  the  question  which  we  here  pro- 
pose. The  certainty  of  the  two  following  data  may,  I 
think,  be  relied  on  ; 1st.  Secretion,  exhalation  and  trans- 
udation are  the  only  means  by  which  a fluid  different  from 
the  blood  can  be  transmitted  to  an  organ.  2d.  Secretion 
and  transudation  are  foreign  to  the  transmission  of  the 
synovia.  Now  from  these  two  certain  data,  can  we  not 
draw  this  conclusion  as  certain,  that  exhalation  is  the 
mode  by  which  the  synovia  is  carried  to  the  articula- 
tions ? But  let  us  add  to  these  negative  proofs  some  con- 
siderations which  establish  this  proposition  positively. 

The  most  striking  relations  are  observed  between  the 
synovia  and  the  fluid  that  lubricates  the  parietes  of  the 
serous  membranes.  1st.  The  relation  of  composition. 
These  two  fluids  are  essentially  albuminous.  Albumen  pre- 
dominates in  both,  though  a little  different  in  each,  as  Mar- 
guerron  has  demonstrated.  Havers  had  previously  point- 
ed out  this  analogy  ; he  knew  that  these  two  fluids  are  co- 
agulable  by  alkohol,  the  acids,  and  caloric,  without  know- 
ing the  principle  to  which  this  property  is  owing.  2d. 
The  relation  of  functions.  Both  are  destined  to  lubricate 
surfaces  on  which  much  motion  takes  place,  to  diminish 
the  friction  which  is  the  inevitable  consequence  of  it  and  to 
prevent  fatal  adhesions.  Both  are  in  the  same  state  on 
their  respective  surfaces  ; it  is  merely  a dew  spread  upon 
these  surfaces,  and  s,oon  taken  up  from  them.  3d.  The 


SYNOVIAL  SYSTEM. 


173 


relation  of  affections.  Inflammation  dries  up  the  source  of 
both,  and  produces  adhesions,  more  common  in  the  serous 
membranes  and  more  rare  in  the  articulations  in  which 
they  produce  anchylosis.  Both  are  subject  to  preter- 
natural enlargement,  which  is  designated  by  a common 
word,  viz.  dropsy.  4th.  The  relation  of  absorption.  The 
lymphatic  system  is  for  both  the  way  by  which  they  re- 
enter the  circulation,  after  having  remained  sufficiently 
long  upon  their  respective  surfaces. 

Do  not  these  various  resemblances,  which  with  some 
slight  differences  of  composition  only,  so  evidently  con- 
nect the  synovia  with  the  fluid  of  the  serous  membranes, 
lead  us  to  this  very  simple  consequence,  viz.  that  these 
two  fluids  being  analogous  in  all  other  respects  must  be 
so  also  as  to  the  manner  in  which  they  are  separated  from 
the  mass  of  blood?  Now  it  is  a point  in  physiology  at 
the  present  day  generally  acknowledged,  that  the  fluid  of 
the  serous  membranes  is  brought  to  them  by  exhalation  ; 
then  we  are  evidently  lead  by  induction  to  this  which 
answers  the  question  proposed  above  ; The  synovia  is 
transmitted  by  exhalation  to  the  articular  surfaces. 

This  rigorous  and  accurate  conclusion  drawn  from  ob- 
vious and  uniform  facts  will  become,  I think,  a demon- 
strated truth,  when  to  the  analogies  already  established 
we  shall  add  that  of  the  membranous  organ,  the  essential 
seat  of  the  exhalation  of  the  synovia. 

II.  Bemarks  upon  the  Synovia. 

Thus  separated  from  the  mass  of  blood,  the  synovia  has 
the  appearance  of  a white,  viscid  and  transparent  fluid. 
It  ropes,  like  some  syrups,  when  it  flows  from  the  articu- 
lations. This  unctuous  property  renders  it  peculiarly  fit 
to  lubricate  the  articular  surfaces  which  rub  together,  and 
to  protect  them  from  violent  shocks. 

Its  quantity  varies  ; there  are  articulations  which  con- 
tain much  of  it ; that  of  the  ankle  has  always  appeared  to 


174 


SYNOVIAL  SYSTEM. 


me  to  have  the  most  of  it.  Then  come  the  ilio-femoral, 
the  scapulo-humeral,  the  humero-cubital,  &c.  There  are 
others  in  ^hich  there  is  scarcely  any  ; such  are  the  sterno- 
clavicular, the  sterno-costals,  the  costo-vertebrals,  &c.  It 
is  not  the  smallness  of  the  synovial  surfaces  that  occasions 
in  these  articulations  the  constant  dryness  that  is  observed 
in  them ; for  the  synovial  sacs  of  the  larynx,  which  are 
much  smaller,  are  much  more  moist. 

Besides,  the  s)movia  does  not  vary  in  quantity  in  each 
articulation,  like  the  serum  in  the  serous  membranes. 
Those  who  have  opened  peritoneums,  pleuras,  pericar- 
diums,  &c.  must  have  seen  that  hardly  two  are  similar  ; 
sometimes  there  is  only  a mere  dew,  at  others  there  is  a 
real  collection  of  fluid.  Here  on  the  contrary  there  is 
always  nearly  the  same  quantity ; which  is  owing  to  this, 
that  the  synovial  surface  does  not  feel  as  easily  as  the 
serous  surfaces,  the  sympathetic  influences  of  the  other 
organs  when  diseased. 

The  synovia  is  not  subject  to  the  different  alterations 
which  tlie  serous  fluids  exhibit.  I have  never  seen  upon 
the  articular  surfaces  what  are  called  false  membranes 
from  inflammation.  The  preternatural  collections  of  syno- 
via never  contain  those  white  flakes,  so  common  in  the 
serous  collections.  I do  not  know  of  an  example  of 
milky  serum  effused  in  an  articulation.  One  of  the  most 
frequent  alterations  of  the  synovia  is  that,  I think,  in 
which  it  takes  the  consistence  of  a jelly  and  is  of  a reddish 
colour,  analogous,  if  I may  be  allowed  the  comparison,  to 
currant  jelly.  Now  this  alteration  is  wholly  foreign  to 
the  serous  fluids. 

These  essential  differences  which  the  synovia  and  the 
serum  exhibit  in  their  alterations,  evidently  suppose  a 
diversity  of  nature  in  the  principles  which  compose  them 
in  the  natural  state.  The  viscidity  of  one  and  the  greater 
fluidity  of  the  other,  also  declare  it,  as  Fourcroy  has  ob- 
served. This  diversity  of  nature  appears  to  depend  espe- 


SrNOVIAL  SYSTEM. 


175 


daily  upon  a peculiar  substance  which  enters  into  the 
composition  of  the  synovia,  which  few  animal  fluids 
possess,  which  Marguerron  who  has  observed  it  desig- 
nates by  the  name  of  albumen  of  a peculiar  nature,  and 
which  should  be  the  object  of  new  researches. 

I shall  not  give  here  the  details  of  the  analysis  of  the 
synovia;  they  belong  to  animal  chemistry. 

III.  Of  the  Synovial  Membranes. 

We  have  seen  all  the  great  cavities  lined  by  the  serous 
membranes,  which  form  by  their  folds  species  of  sacs 
without  an  opening,  and  which  embrace  both  the  organs 
and  the  parietes  of  these  cavities.  There  exists  in  all  the 
moveable  articulations  membranes  precisely  analogous,  the 
uses  of  which  are  the  same,  the  nature  of  which  is  not 
different  and  which  I call  synovial,  because  their  parietes 
constantly  exhale  and  absorb  synovia. 

Forms. 

Every  synovial  membrane  thep  should  be  considered 
as  a sac  without  an  opening,  spread  upon  the  organs  of 
articulation,  upon  the  diarthrodial  cartilages,  upon  the 
internal  face  of  the  lateral  and  capsular  ligaments,  upon 
the  whole  of  the  inter-articular  ligaments  when  they  exist, 
upon  the  prominent  fatty  bunches  in  some  articular  cavi- 
ties, &c.  It  is  from  it  that  these  different  organs  borrow 
the  smooth,  polished  and  shining  appeai’ance  which  char- 
acterizes them  in  these  cavities,  and  which  they  have 
not  elsewhere.  Just  as  by  dissecting  carefully  the  gastric 
organs,  the  peritoneum  can  be  removed,  its  sac  remain- 
ing whole,  so  we  can  conceive  of  the  possibility  of  sepa- 
rating this  membrane,  notwithstanding  the  intimate  adhe- 
sions it  forms  in  some  places.  All  the  parts  that  it  em- 
braces are  out  of  the  articular  cavity,  though  projecting 
into  this  cavity,  as  the  lungs  are  found  on  the  exterior  of 


176 


SYNOVIAL  SYSTEM. 


the  sac  formed  by  the  pleura,  the  liver  on  the  exterior  of 
the  peritoneal  sac,  &c.  &c. 

The  synovial  membrane  is  found  in  all  the  moveable 
articulations,  the  greatest  number  of  which  has  only  it 
and  the  lateral  ligaments.  What  is  commonly  called  the 
fibrous  capsule  is  only  met  with  around  some  of  the  ar- 
ticular surfaces.  The  connexions  of  the  humerus,  the 
femur,  and  one  or  two  other  bones,  the  extremities  of 
wdiich  are  joined  by  enarthrosis,  present  the  only  exam- 
ples of  it.  There  are  seen  in  these  articulations  two  very 
distinct  coverings.  One  which  is  fibrous  is  external,  and 
is  found  arranged  in  the  form  of  a sac  open  above  and 
belowj  embracing  by  its  two  great  openings  the  surfaces 
of  the  two  bones,  and  being  intermixed  around  them 
with  the  periosteum,  the  fibres  of  both  interlace  with  each 
other.  The  other  cellular,  which  is  the  synovial  mem- 
brane, lines  the  first  on  the  interior,  separates  afterwards 
from  it  when  it  arrives  towards  the  two  diarthrodial 
cartilages,  and  is  reflected  upon  them,  instead  of  being 
united  to  the  periosteum.  Boyer  has  pointed  out  this 
arrangement  in  regard  to  the  femur. 

In  all  the  ginglymoid  articulations,  as  in  those  of  the 
elbow',  the  knee,  the  phalanges,  the  hand,  the  foot,  &c. 
&c.  the  fibrous  capsule  is  wholly  wanting.  The  fibres, 
instead  of  extending  and  interlacing  in  the  form  of  a mem- 
brane, are  collected  into  fasciculi  more  or  less  thick,  which 
form  the  lateral  ligaments.  Thei’e  is  only  found  in  them 
the  internal  layer  of  the  enarthrodial  articulations,  that  is  to 
say  the  synovial  membrane,  w'hich  does  not  contract  here 
any  adhesion  with  the  periosteum,  but  is  reflected  upon 
the  cartilages.  By  taking  it  at  the  place  of  this  reflection, 
it  can  be  detached  far  enough  to  prove  that  it  has  an 
external  organization  wholly  different  from  that  which 
the  idea  of  a capsular  ligament  at  first  presents  to  the 
mind.  This  arrangement  is  very  easily  perceived  by 
the  least  dissection,  at  the  knee  behind  the  tendon  of  the 


SYNOVIAL  SYSTEM, 


177 


cruraeus  and  the  inferior  ligament  of  the  patella,  at  the 
elbow  under  the  tendon  of  the  triceps,  at  the  phalanges 
under  that  of  the  extensor,  &c.  All  the  arthrodial  articula- 
tions have  also  an  analogous  organization,  as  will  be  seen  in 
the  Descriptive  Anatomy  ; so  that  it  is  ascertained  that 
the  fibrous  capsules  exist  but  in  a very  small  number  of 
articulations,  that  almost  all  have  only  synovial  sacs 
which  are  spread  out  and  reflected  upon  the  osseous  sur- 
faces, without  being  attached  around  them,  as  all  authors 
have  said. 

I have  proved  this  remarkable  difference  of  the  articula- 
tions by  many  dissections.  Some  anatomists  were  in  the 
way  to  discover  it,  when  they  observed  that  the  differ- 
ent capsules  appeared  to  be  wholly  formed  of  cellular  tex- 
ture. It  is  in  fact  the  texture  of  the  synovial  membrane, 
which  differs  essentially  in  this  from  the  fibrous  capsules. 
The  mode  of  capsule  for  all  articulations  may  be  pre- 
served, if  it  is  wished,  but  different  ideas  must  then  neces- 
sarily be  attributed  to  it.  Compare,  for  example,  the 
fibrous  capsule  of  the  femur  with  the  synovial  capsule  of 
the  knee ; you  will  find  on  the  one  hand,  1st,  a cylin- 
drical sac  with  two  great  openings  for  the  osseous  extre- 
mities, and  with  many  small  ones  for  the  vessels ; 2d,  a 
fibrous  interlacing,  similar  to  that  of  the  tendons,  the 
aponeuroses,  &c. ; 3d,  a mode  of  sensibility  analogous  to 
that  of  these  organs  ; 4th,  the  use  of  retaining  strongly 
in  place  the  articulated  bones,  which  have  only  this  bond 
to  strengthen  their  union.  On  the  other  hand  you  will 
observe,  1st,  a sac  without  an  opening;  2d,  a cellular 
structure,  the  same  as  that  of  the  serous  membranes  ; 3d, 
a sensibility  of  the  same  nature  as  theirs ; 4th,  the  simple 
function  of  containing  the  synovia  and  separating  it,  the 
bones  being  tied  by  strong  ligaments.  Besides,  the  dif- 
ferent reagents  have  upon  the  fibrous  capsules  an  influence 
wholly  different  from  that  which  they  exert  upon  the 
synovial.  Ebullition  yellows  them,  renders  them  semi- 
VOL.  III.  23 


178 


SYNOVIAL  SYSTEM. 


transparent,  softens  them  like  tendons  and  gradually  melts 
them  like  gelatine.  The  synovial  ones  boiled  remain 
whitish,  and  furnish  but  little  of  this  substance.  I would 
observe  that  the  yellowish  tinge  and  semi-transparency 
of  the  boiled  fibrous  capsules  are  a certain  means  of  dis- 
tinguishing the  articulations  in  which  they  exist  and  those 
which  are  destitute  of  them. 

The  existence  of  the  synovial  capsule  in  the  greatest 
number  of  articulations  in  which  it  is  found  alone,  is 
placed  beyond  a doubt  l)y  the  slightest  inspection.  In 
those  in  which  it  is  united  to  a fibrous  capsule,  it  is  very 
clearly  distinguished  in  several  places.  Thus  in  the  thigh, 
it  is  found  upon  the  interarticular  ligament,  upon  the 
fatty  bunch  in  the  cotyloid  cavity,  and  upon  the  neck  of 
the  bone  at  the  places  where  it  leaves  the  fibrous  capsule, 
to  be  reflected  upon  the  cartilages,  &c. ; but  its  adhesion 
to  these  cartilages  and  to  the  internal  face  of  the  capsule, 
may  excite  some  doubts  as  to  its  arrangement  in  the  form 
of  a sac  everywhere  closed,  which  we  have  attributed  to 
it ; it  is  then  essential  to  offer  some  considerations  that 
may  dissipate  these  doubts. 

1st.  However  strong  the  adhesions  of  the  synovial  mem- 
brane may  be,  they  can  be  destroyed  without  a solution  of 
continuity,  by  a slow,  careful  dissection  begun  at  the  place 
where  the  membrane  is  reflected  from  the  cartilage  upon 
the  capsule.  It  can  be  taken  away  in  parts  after  long  con- 
tinued maceration.  2d.  In  consequence  of  certain  inflam- 
mations, this  membrane  acquires  a thickness  and  opacity 
which  enable  us  to  distinguish  it  from  all  the  neighbour- 
ing organs,  from  those  even  to  which  it  adheres  the  most. 
3d.  The  synovial  bags  are  all  as  adherent  as  the  articular 
synovial  one,  to  the  cartilages  of  their  sheath  and  to  this 
sheath  itself ; yet  every  one  acknowledges  their  distinct 
existence.  4th.  There  are  articulations  with  a fibrous 
capsule,  in  which  the  fibres  are  separated  so  as  to  leave  a 
space  between  them  through  which  the  synovia  would 


SYNOVIAL  SYSTEM. 


179 


escape,  if  the  synovial  membrane  did  not  line  them. 
When  air  is  forced  into  the  articulation,  this  membrane 
rises  up  in  these  spaces  and  exhibits  a texture  wholly 
different  from  that  of  the  capsule.  Bertin  observed  this, 
but  thought  that  these  pellicles  were  insulated,  and  did 
not  see  that  they  depended  upon  the  continuity  of  the 
membrane  which  is  extended  over  the  whole  articulation. 
5th.  We  have  observed  in  the  article  upon  the  serous 
system,  that  the  smooth  and  polished  appearance  which 
the  surface-  of  the  organs  and  the  cavities  exhibit,  is 
always  given  to  them  by  these  membranes,  and  that 
they  never  derive  it  from  their  peculiar  structure;  now 
we  shall  see  that  the  synovial  membrane  has  almost  the 
same  texture  as  the  serous  ; then  it  appears  that  in  the 
places  in  which  the  articular  organs  exhibit  this  charac- 
ter, it  is  from  it  that  they  receive  it,  though  it  cannot  be 
distinguished  as  well  upon  these  organs,  as  where  it  is 
free.  Besides,  the  articulations  that  are  evidently  desti- 
tute of  this  membrane,  have  not  this  smooth  and  polished 
appearance.  Such  are  the  surfaces  of  the  symphysis  pubis, 
and  of  the  sacro-iliac  symphysis  which  are  found,  though 
contiguous,  unequal,  rough,  &c.  We  have  also  proved 
that  this  organic  form  is  never  owing  to  compression. 

From  these  different  considerations  we  may  be  easily 
convinced,  I think,  that  notwithstanding  the  adhesion 
of  the  synovial  membrane  at  different  points,  it  should 
be  considered  in  a manner  precisely  analogous  to  that  of 
the  serous  membranes,  that  is  to  say  as  a real  sac  without 
an  opening,  everywhere  contiguous  and  spread  upon  all 
the  organs  of  the  articulation.  Besides,  do  not  the  fibro- 
serous  membranes  exhibit  similar  adhesions,  though  the 
separate  existence  of  the  two  layers  which  compose  them 
is  generally  admitted  ? 

From  the  idea  we  have  formed  of  the  synovial  mem- 
brane, it  is  easy  to  conceive  how  certain  organs  pass 
through  the  articulation,  without  the  escape  of  the  syno- 


180 


SYMOVIAL  SYSTEM. 


via  by  the  opening  which  receives  or  by  that  which  trans- 
mits them  The  synovial  membrane  then  reflected  around 
these  organs,  forms  for  them  a sheath  which  separates 
them  from  the  fluid  and  keeps  them  distinct  from  the 
articulation.  Thus  the  tendon  of  the  biceps  is  no  more 
contained  in  the  articulation  of  the  arm  with  the  scapula, 
than  the  umbilical  vein,  the  urachus,  &c.  are  in  the  perito- 
neal cavity.  With  the  least  care  it  may  be  separated  from 
the  portion  of  membrane  which  forms  its  sheath. 

The  preceding  considerations  lead  us  also  to  find  a per- 
fect identity  in  the  synovial  capsules  of  the  tendons  and 
the  articular  synovial  ones.  In  the  preceding  example, 
these  two  kinds  of  membranes  are  evidently  continuous  ; 
for  the  capsule  of  the  groove  of  the  biceps  is  of  the  same 
nature  as  that  of  the  tendons  which  have  a separate  one 
from  it,  as  the  flexors,  for  example. 

Organization. 

We  have  just  seen,  that  the  synovial  membrane  resem- 
bles very  much  in  its  external  conformation  the  class  of 
serous  membranes,  it  does  not  less  so  in  its  internal  organi- 
zation. This  organization  is  cellular,  as  is  proved  by 
dissection,  inflation  and  especially  maceration.  The  sac 
which  the  ganglions  form  is  evidently  only  a production 
of  the  cellular  organ  ; now  it  is  known  that  this  sac  exhales 
and  contains  a fluid  similar  to  the  synovia.  Wherever 
the  synovial  membrane  Is  free,  it  is  attached  externally  to 
this  organ  and  is  confounded  with  it  in  so  direct  a man- 
ner, that  by  raising  successively  its  different  layers  they 
are  seen  to  be  gradually  condensed  and  finally  united 
together  to  form  it.  So  that  in  the  serous  membranes  no 
fibre  is  visible.  It  becomes  transparent  when  it  is  sepa- 
rated accurately  on  both  sides,  which  is  easily  done  at 
tlie  knee  to  a great  extent. 

I shall  not  go  hack  to  the  various  proofs  which  establish 
tlic  cellular  structure  of  the  serous  system ; almost  all 


SYNOVIAL  SYSTEM. 


181 


these  proofs  are  applicable  to  the  synovial  system,  which 
appears  to  be  but  a net-work  of  absorbents  and  exhalants. 
Hence  it  is  easy  to  understand  what  the  red  and  fatty 
bunches  are  that  are  found  around  the  articulations. 
They  perform  in  regard  to  this  membrane  the  functions 
of  the  abundant  cellular  texture  which  envelops  the  peri- 
toneum, the  pleura,  &c.  &c.  It  is  there  that  the  blood 
vessels  divide  ad  infinitum  before  arriving  at  the  mem- 
brane where  their  ramifications,  successively  decreasing, 
finally  terminate  in  the  exhalants. 

If  a remarkable  redness  sometimes  distinguishes  these 
bunches  from  the  cellular  texture,  it  is  because  the  vessels 
are  more  concentrated  and  nearer  together  in  them.  For 
example,  in  the  articulation  of  the  hip,  the  synovial 
membrane  of  which,  almost  everywhere  adherent,  only 
corresponds  in  the  fissure  of  the  cotyloid  cavity  with  the 
cellular  texture,  nature  has  placed  there  almost  all  the 
arterial  ramifications  that  furnish  the  synovia  ; hence  the 
reddish  tinge  of  the  cellular  bunch  that  is  found  there. 
On  the  contrary,  at  the  knee  where  much  cellular  texture 
surrounds  the  whole  external  face  of  the  synovial  sac,  the 
vessels  more  scattered  leave  to  tliis  texture  the  same 
colour  as  that  of  the  external  face  of  the  serous  mem- 
branes, &c.  This  redness  of  some  pretended  synovial 
glands,  the  only  character  that  distinguishes  them,  is  then 
as  it  were  merely  accidental  5 it  no  more  indicates  their 
glandular  nature,  than  it  proves  it  in  the  pia-mater,  in 
which  it  is  owing  to  the  same  cause. 

Though  the  synovial  membrane  is  very  analogous  to' 
the  serous  surfaces,  it  must  however  exhibit  differences 
of  texture,  since  the  fluid  it  exhales  is  a little  different. 
In  fact,  by  examining  it  at  the  femoro-tibial  articulation, 
where  it  can  be  found  in  considerable  pieces,  it  is  seen  to 
be  more  dense  and  compact  than  the  serous  membranes. 
Its  texture  has  not  the  suppleness  of  theirs  ; when  dried, 
it  is  much  more  brittle;  it  remains  stiff,  whilst  the  serous 


182 


SYNOVIAL  SYSTEM. 


texture  is  moved  in  all  directions  without  the  least  effort. 
It  resists  maceration  longer. 

Properties. 

The  properties  of  texture  become  evident  in  articular 
dropsies,  in  which  the  synovial  membranes  are  at  first 
much  distended,  and  in  which  they  contract  after  the 
puncture,  an  operation  however  that  is  very  rare.  Yet 
it  appears  that  these  membranes  are  only  susceptible  of  a 
slow  and  gradual  extension.  We  know  that  suddenly 
separated  in  luxations,  their  parietes  tear  instead  of  stretch- 
ing ; they  unite  again  after  the  reduction. 

Among  the  vital  properties,  the  organic  sensibility  is  the 
only  one  of  this  system  in  the  ordinary  state,  as  I have 
proved  by  many  experiments  on  living  animals  in  which 
these  surfaces  have  been  laid  bare  and  irritated  by  various 
agents.  But  the  increase  of  life  which  inflammation  pro- 
duces by  raising  this  sensibility,  transforms  it  into  animal 
sensibility  ; this  is  what  is  observed,  1st,  in  the  wounds  in 
which  these  membranes  are  exposed  to  the  contact  of  the 
air ; 2d,  in  the  long  continued  irritation  they  experience 
from  foreign  bodies  preternaturally  developed  in  the  ar- 
ticulation ; 3d,  in  the  various  affections  of  the  articular 
surfaces,  &c. 

This  kind  of  sensibility  of  the  synovial  membranes 
serves  to  confirm  what  I have  already  established  above, 
viz.  that  most  of  the  articulations,  the  ginglymoid  espe- 
cially, are  destitute  of  fibrous  capsules.  In  fact,  I have 
observed  that  these  capsules,  as  well  as  the  lateral  liga- 
ments, have  a kind  of  animal  sensibility,  which  is  de- 
veloped by  pulling  them  ; so  that  if  all  the  neighbouring 
organs  of  an  articulation,  except  the  synovial  membrane 
and  the  lateral  ligaments,  are  remoted  and  this  articu- 
lation afterwards  twisted,  the  animal  gives  signs  of  the 
most  acute  pain.  But  afterwards  cut  the  ligaments,  and 
leave  only  the  synovial  membrane,  the  twisting  no  longer 


SYNOVIAL  SYSTEM. 


1S3 


gives  pain ; then  there  is  no  fibrous  capsule  united  to  the 
synovial.  This  experiment,  which  is  easily  repeated 
upon  the  fore  or  hind  legs,  enables  us  to  recognise  every- 
where the  articulations  in  which  the  synovial  membrane 
exists  alone,  and  those  in  which  it  is  found  united  to  a 
fibrous  capsule.  This  being  of  the  same  texture  as  the 
lateral  ligaments,  produces  the  same  pains  when  it  is 
pulled,  as  is  proved  elsewhere  by  experiments  made  upon 
the  articulations  clothed  with  these  capsules. 

The  alternate  exhalation  and  absorption  which  takes 
place  upon  the  serous  surfaces,  prove  the  insensible  con- 
tractility in  them. 

I have  already  observed  that  the  synovial  surfaces  per- 
form but  a small  part  in  the  sympathies,  that  they  feel 
but  very  slighly  the  affections  of  the  other  organs.  Whilst 
in  the  acute  affections  of  the  important  viscera,  the  skin, 
the  mucous  surfaces,  the  cellular  texture,  the  nerves,  &c. 
&c.  have  a greater  or  less  sympathetic  derangement,  all 
the  synovial  membranes  remain  unaffected ; they  do  not 
become  the  seat  of  irregular  pains,  nor  of  a more  active 
or  slower  exhalation.  They  resemble  in  this  respect  the 
osseous,  cartilaginous,  and  even  fibrous  systems.  Thus 
it  is  not  necessary  that  the  physician  should  seek  in  the 
synovial  system  a frequent  seat  of  the  accessory  symp- 
toms in  diseases,  of  that  class  of  symptoms  which  does 
not  belong  to  the  injury  of  the  diseased  organ  itself,  but 
to  its  relations  with  other  parts. 

In  the  pains  of  the  articulations,  there  are  certainly  cases 
in  which  the  synovial  membrane  is  diseased,  and  others 
in  which  the  fibrous  organs  alone  are  affected.  The  dis- 
tinction of  these  cases  should  be  sought. 

Functions. 

The  synovial  membrane  adds  nothing  to  the  solidity 
of  the  articulation.  The  fibrous  capsules  and  the  lateral 
ligaments  alone  serve  this  purpose.  The  smooth  surface 


iS4 


SYNOVIAL  SYSTEM. 


which  the  articular  extremities  derive  from  this  mem- 
brane, favours  their  motions ; it  can  even  in  this  way 
assist  the  muscular  action  ; thus  the  portions  of  synovial 
membrane  which  are  found  at  the  knee  behind  the  cru- 
raeus,  at  the  elbow  under  the  triceps,  at  the  phalanges 
under  the  flexors,  &c.  perform  in  respect  to  these  muscles, 
the  same  functions  as  the  tendinous  synovial  bags.  They 
are  to  their  tendons,  what  the  cellular  sac  which  separates 
the  tendons  of  the  psoas  and  the  iliacus  from  the  crural 
arch,  is  to  them. 

The  principal  use  of  the  membrane  of  which  we  are 
treating  is  in  relation  to  the  synovia.  It  exhales  by 
numerous  orifices  this  fluid  which  remains  there  for  some 
time,  and  afterwards  re-enters  the  circulation  by  absorp- 
tion. Its  parietes  are  then  the  seat  of  exhalation,  as  the 
kidneys,  for  example,  are  that  of  the  secretion  of  urine. 
The  reservoir  of  the  exhaled  fluid  is  the  sac  without  open- 
ing which  it  forms,  as  the  bladder  is  that  of  the  urine  that 
comes  from  the  kidneys.  The  excretory  vessels  of  this 
same  fluid  are  the  absorbents  which  carry  it  into  the  mass 
of  blood,  as  the  urethra  carries  the  urine  from  the  bladder. 
There  is  under  these  different  relations  more  analogy  than 
there  at  first  seems  to  be,  between  secretion  and  exhalation. 

The  phenomena  of  the  continuance  of  the  synovia  in 
this  membranous  reservoir,  have  relation  to  the  synovia 
itself  or  to  the  articular  surfaces.  The  first  consist  in  a 
peculiar  but  unknown  alteration  which  it  undergoes  be- 
tween the  exhalant  and  absorbent  systems.  The  second 
contribute  to  facilitate  the  articular  motions.  The  unctu- 
ous and  slippery  coat  which  the  serous  surfaces  receive 
from  the  synovia,  is  remarkably  adapted  to  this  use,  as  I 
have  observed. 

Natural  Development, 

In  the  foetus  and  in  infancy  most  of  the  synovial  mem- 
branes are  much  larger  in  proportion  than  in  the  after 


SYNOVIAL  SYSTEM. 


185 


ages,  because  the  articular  surfaces  have  a greater  extent 
in  the  cartilaginous  than  in  the  osseous  state ; but  they 
are  then  extremely  delicate.  The  synovia  is  not,  as  the 
serous  fluids  are  at  this  age,  more~unctuous  and  of  great- 
er consistence  ; it  appears  even  to  be  less  so.  Before 
birth  it  is  in  small  quantity,  no  doubt  because  the  motions 
are  trifling. 

In  old  age  I have  observed  that  the  synovial  membrane 
becomes  moi’e  dense  and  compact.  It  loses  in  part  its 
white  colour  and  becomes  grey  ; less  synovia  is  exhaled 
from  it.  It  is  not  like  the  serous  surfaces,  exposed  to 
dropsies.  The  rigidity  it  acquires  makes  motion  painful. 
It  never  ossifies  except  preternatural ly.  The  phosphate 
of  lime  which  gradually  invades  cartilage,  does  not  take 
hold  of  it.  I do  not  know  an  instance  of  an  old  person 
in  whom  bone  has  been  found  naked  in  an  articulation. 

Preternatural  Development. 

I have  already  observed  in  the  article  on  the  fibrous 
capsules,  that  when  the  head  of  a bone  remains  displaced 
in  a luxation,  it  is  not  a membrane  analogous  to  these 
capsules  that  is  developed  around  it ; it  is  a real  cyst, 
smooth  on  its  internal  surface,  moistened  with  serum, 
formed  at  the  expense  of  the  cellular  texture,  and  present- 
ing, with  a little  more  thickness,  the  true  appearance  of 
the  synovial  membranes;  it  is  a preternatural  synovial 
membrane.  The  motions  imparted  to  the  displaced  limb 
appear  to  increase  the  serous  exhalation  in  this  new  mem- 
brane ; hence  no  doubt  the  great  advantage  of  these  mo- 
tions, in  order  to  re-establish  in  part  the  mobility  of  the 
bones  which  remain  out  of  their  sockets.  I have  seen  a 
dancer,  the  head  of  whose  humerus  was  lodged  in  the 
hollow  of  the  axilla,  after  a luxation  that  was  not  reduced, 
perform  very  varied  motions  with  it. 

TOL.  in.  24 


IS6 


SY.NOVIAL  SYSTEM, 


ARTICLE  SECOND. 


SYNOVIAL  SYSTEM  OF  THE  TENDONS. 

This  system  noticed  by  many  authors  and  described 
by  Fourcroy,  Soemmering,  &c.  is  precisely  of  the  same 
nature  as  the  preceding,  from  which  it  differs  only  by  its 
situation  ; it  is  often  even  confounded  with  it.  Thus  the 
synovial  membrane  of  the  tendon  of  the  biceps  is  con- 
tinuous with  that  of  the  scapulo-humeral  articulation ; 
thus  those  of  the  gemelli  are  so  with  the  synovial  mem- 
brane of  the  femoro-tibial  articulation ; it  is  the  same 
membrane  which  belongs  at  the  same  time  to  the  tendon 
and  to  the  articulation.  A remarkable  example  of  it  is 
seen  in  the  extensors  of  the  leg  and  the  ham,  to  the  ten- 
dons of  which  the  same  articular  synovial  membrane  of 
the  knee  serves  for  a capsule. 

But  very  few  tendinous  synovial  membranes  are  found 
in  the  trunk;  almost  all  are  on  the  extremities  where  they 
serve  to  assist  the  slipjjing  of  the  tendons.  They  are 
met  with,  1st,  where  a tendon  is  reflected  at  an  angle 
upon  a bone,  as  around  those  of  the  great  lateral  peroneus, 
the  peroneus  medius,  the  obturator  internus,  the  great 
oblique  of  the  eye,  &c.  ; 2d,  where  a tendon  slips  upon 
an  osseous  surface  without  being  reflected,  as  at  the  ex- 
tremity of  the  tendo  Achillis,  as  under  that  of  the  great 
glutseus,  and  those  of  the  psoas  and  iliacus  united ; 3d, 
whei'e  a tendon  slips  in  a fibrous  capsule,  as  in  those  of 
all  the  flexors,  &c.  Their  extent  is  uniformly  in  propor- 
tion to  that  of  the  tendons  upon  which  they  are  spread. 

Forms  ; Relations  ; Synovial  Fluid. 

The  tendinous  synovial  membranes,  are,  like  the  articu- 
lar ones,  sacs  without  an  opening,  spread  on  the  one 


SYNOVIAL  SYSTEM. 


1S7 


hand  on  the  tendon  and  on  the  other  upon  the  neighbour- 
ing organs.  These  sacs  are  differently  shaped  according 
to  the  arrangement  of  the  tendon,  but  their  general  con- 
formation is  uniform.  We  see  from  this  that  every  ten- 
dinous synovial  membrane  has  two  faces,  one  which 
forms  the  interior  of  the  sac,  which  is  everywhere  free 
and  contiguous  to  itself,  the  other  which  lines  the  adja- 
cent organs. 

The  free  surface  is  constantly  moistened  by  a fluid  pre- 
cisely similar  to  that  of  the  articulations,  furnished  like 
it  by  exhalation,  and  not  as  authors  have  said  by  red 
bodies  situated  in  the  neighbourhood,  bodies  of  which 
oftentimes  there  is  no  trace  visible,  and  which,  when 
they  exist,  have  nothing  glandular  in  them.  This  fluid 
is  in  general  much  less  abundant  than  in  the  articulations, 
at  least  in  the  dead  body.  But  there  are  varieties  in  the^ 
different  synovial  bags  ; those  of  the  tendo  Achillis,  of 
the  tendons  of  the  psoas  and  iliacus  united,  of  that  of  the 
obturator  internus,  &c.  are  always  more  moist  than  those 
of  the  flexor  tendons,  &c. 

Is  it  to  the  absence  of  synovia  that  must  be  attributed 
the  species  of  crepitation  which  the  tendons  sometimes 
make  in  their  motions  ? I know  not.  I would  only 
observe  that  this  crepitation  has  some  analogy  with  the 
crackling  noise  of  the  joints  of  the  fingers  when  they  are 
bent  quickly,  a noise,  which  does  not  depend,  as  might 
be  supposed,  on  the  friction  of  the  osseous  surfaces  ; in 
fact,  when  it  has  been  once  produced,  it  cannot  be  again, 
though  there  may  be  friction  again.  Besides  it  is  knowm 
that  this  crackling  noise  arises  from  the  forced  elonga- 
tion of  the  phalanges,  and  consequent!}^  from  the  separa- 
tion of  their  articular  surfaces,  as  well  as  from  the  flexion. 

The  increase  of  the  fluid  of  the  tendinous  synovial 
membranes  forms  a species  of  dropsy  which  is  called 
ganglion,  a tumour  which  never  exists  in  the  synovial 
membranes  of  the  fingers,  no  doubt  on  account  of  the  want 


188 


SYNOVIAL  SYSTEM. 


of  extensibility  of  the  fibrous  capsules.  It  should  not  be 
thought  however  that  all  these  tumours,  which  are  cured 
by  bursting  them  by  strong  pressure  and  thus  effusing  the 
fluid  into  the  cellular  membrane,  have  for  their  base  a 
natural  synovial  membrane.  Most  frequently  they  are 
preternatural ; they  arc  c}^sts  which  are  formed  in  the  cel- 
lular texture.  In  fact  these  tumours  are  often  found  in 
the  course  of  the  great  extensor  of  the  thumb,  where  there 
is  no  synovial  membrane.  After  rheumatic  pains  I have 
seen  a considerable  collection  of  fluid  in  the  small  syno- 
vial membrane  of  the  tendo  Achillis  ; it  gradually  disap- 
peared. I have  observed  another  analogous  one  in  the 
bag  of  the  psoas  of  a dead  body.  The  fluid  was  reddish 
and  of  the  consistence  of  currant  jelly.  The  action  of 
nitric  acid  immediately  coagulated  it  into  a white  mass, 
ranalogous  to  the  white  of  an  egg  hardened. 

The  adhering  surface  of  the  tendinous  synovial  mem- 
branes is  spread,  1st,  on  the  one  hand  upon  the  tendons, 
with  which  it  is  more  or  less  intimately  united.  It  is 
easily  detached  from  those  of  the  internal  obturator,  the 
psoas,  &c.  It  is  closely  connected  v/ith  those  of  the  flex- 
ors. 2d.  On  the  other  hand,  it  commonly  lines  the  peri- 
osteum, which,  in  this  place,  is  penetrated  with  gelatine, 
and  forms  a fibro-cartilage.  Its  mode  of  relation  is  there 
analogous  to  that  of  the  articular  synovial  membrane  with 
the  cartilage  of  the  bone.  Sometimes  it  is  reflected  upon 
a fibrous  capsule  after  having  lined  the  tendon ; such  are 
those  which  arc  in  the  neighbourhood  of  the  scapulo- 
humeral articulation.  In  some  cases,  after  having  lined 
the  tendon,  they  mount  up  to  the  fleshy  fibres,  as  on  the 
obturator  internus.  3d.  By  reflecting  from  the  tendon 
upon  the  neighbouring  organs,  they  answer  in  general  in- 
stead of  much  cellular  texture  ; but  in  the  grooves  of  the 
flexors,  it  is  the  fibrous  sheaths  which  they  clothe. 

In  all  the  great  motions,  the  tendinous  synovial  mem- 
branes, stretched  more  or  less,  undergo  various  locomo- 


SYNOVIAL  SYSTEM. 


189 


lions,  always  less  however  than  those  of  the  serous  sur- 
faces. 

The  very  various  forms,  which  the  sac  without  open- 
ing-of  the  tendinous  synovial  membranes  exhibits,  can 
be  reduced  to  two  general  modifications.  1st.  Some  are 
rounded  sacs,  species  of  bladders  ; such  are  those  upon 
the  supra-spinatus,  the  psoas,  iliacus,  obturator  internus, 
&c.  All  these  membranes  are  remarkable  for  this,  that 
they  never  cover  the  tendon  entirely,  but  only  on  one 
side ; that  they  never  form  internal  folds  and  that  they 
are  never  surrounded  by  fibrous  sheaths.  2d.  The  others, 
belonging  especially  to  the  flexors,  and  to  the  difierent 
tendons  which  traverse  the  sole  of  the  foot,  form  at  first 
a kind  of  cylindrical  sac  which  lines  the  canal  half  fibrous, 
half  cartilaginous  in  which  the  tendon  slips  ; then  they 
are  reflected  around  it,  cover  it  wholly  and  form  for  it  a 
true  sheath  which  prevents  it  from  being  moistened  by 
the  synovia.  This  kind  of  tendinous  synovial  membrane 
represents  then  truly  two  canals,  at  the  superior  and  in- 
ferior extremities  of  which  are  found  two  cul-de-sacs 
which  unite  them  and  complete  the  sac  without  an  open- 
ing. Internal  folds  are  here  frequently  found  going  from 
one  canal  to  the  other.  All  the  synovial  membranes  of 
the  flexors  have  one  of  them  under  the  tendon. 

Organization  ; Properties  ; Development. 

The  organization  of  the  tendinous  synovial  membranes 
is  precisely  analogous  to  that  of  the  articular  ones.  Prin- 
cipally cellular,  the  texture  of  these  membranes  is  with- 
out any  apparent  fibre  ; its  softness  is  very  evident ; very 
few  blood  vessels  are  distributed  to  it,  though  the  con- 
trary has  been  said ; absorbents  and  exhalants  especially 
predominate  in  it.  These,  filled  with  blood  in  inflamma- 
tion, give  to  the  membrane,  a reddish  tinge,  more  or  less 
deep.  In  this  state  the  synovia  is  not  exhaled  ; sometimes 


190 


SYNOVIAL  SYSTEM. 


even  adhesions  are  formed,  as  I have  observed  in  a sub- 
ject in  whom  the  fibrous  sheaths  and  their  tendons  of  the 
index  and  the  middle  finger  seemed  to  be  united.  The 
inflammatory  phenomena  of  the  tendinous  synovial  mem- 
branes are  especially  remarkable  in  whitlows,  a disease, 
one  species  of  which  has  evidently  its  seat  in  the  syno- 
vial membrane  of  the  fingers,  is  analogous  to  the  inflam- 
mation of  the  pleura,  the  peritoneum,  and  to  that  of  the 
articulations.  It  is  more  dangerous  than  the  inflamma- 
tion  of  the  synovial  membranes  in  the  form  of  bladders 
or  bags,  because  the  fibrous  sheath  which  surrounds  the 
inflamed  membrane,  not  being  able  to  stretch  and  yield 
to  the  swelling,  like  the  cellular  texture  which  surrounds 
the  synovial  bags,  produces  I’eal  strangulations,  which  it 
is  often  necessary  to  remove.  I do  not  know  whether 
the  synovial  texture  of  the  tendons  is  exposed  to  the  slow 
and  tubercular  inflammations,  common  to  the  articular 
serous  and  synovial  systems.  Its  vital  properties  and 
those  of  texture  appear  to  be  precisely  the  same  "as  those 
of  this  last.  Like  it,  it  receives  with  difficulty  the  sym- 
pathetic influence  of  the  other  organs ; it  is  unafiected 
during  the  derangement  of  the  other  systems  in  acute 
diseases  ; it  remains  sound  in  their  alterations  arising  from 
chronic  affections.  I would  observe  also  that  all  its  affec- 
tions are  almost  local.  For  example,  there  is  not,  as  in 
the  serous  system,  species  of  dropsical  diathesis,  that  is 
to  say  of  cases  in  which  all  the  synovial  sacs  are  filled 
at  the  same  time. 

The  tendinous  synovial  membranes,  fine  and  delicate 
in  the  foetus  and  in  infancy,  readily  yield  to  the  nume- 
rous motions  which  constantly  succeed  that  age.  More 
dense  and  compact  in  the  adult,  they  become  rigid  in  old 
age,  exhale  less  fluid,  are  dry,  and  do  not  contribute  a 
little,  by  the  state  in  which  they  are,  to  the  general  slow- 
ness of  the  motions  which  that  age  brings  with  it. 


SYNOVIAL  SYSTEM. 


191 


There  are  many  synovial  membranes  the  existence  of 
which  is  variable  ; such  as,  for  example,  that  of  the  great 
glutaeus,  in  the  place  of  which  there  is  often  found  only 
a cellular  mass.  These  membranes  are  in  general  very 
dry  when  they  exist.  Synovia  can  scarcely  be  discover- 
ed in  them.  They  resemble  in  this  respect  the  articular 
synovial  membranes  of  the  vertebrae,  the  clavicle,  &c. 


GLANDULAR  SYSTEM. 


THIS  system,  one  of  the  most  important  in  the  ani- 
mal economy,  differs  from  most  others  in  this,  that  the 
texture  which  is  peculiar  to  it  is  not  precisely  the  same 
in  all  the  organs  that  compose  it.  The  fibres  of  a muscle 
of  animal  life  would  as  well  serve  for  the  structure  of 
any  other  muscle  of  the  same  system.  The  tendinous 
fibres,  the  cartilaginous,  osseous  textures,  &c.  are  every- 
where the  same.  On  the  contrary,  the  texture  of  the 
liver  would  not  serve  to  compose  the  kidney,  nor  that  of 
this  last  the  salivary  glands.  The  glandular  system  then 
has  a resemblance  in  its  different  parts  only  by  certain 
general  attributes  which  have  many  exceptions. 

Authors  have  given  the  name  of  glands  to  organs  to 
which  it  does  not  belong ; such  as  the  thyroid,  the  pineal, 
the  lymphatic  glands,  those  especially  that  are  in  the 
neighbourhood  of  the  bronchia,  the  thymus,  the  supra- 
renal, &c.  We  should  call  by  this  name  only  a bod)’- 
from  which  flows,  by  one  or  many  ducts,  a fluid  which 
this  body  separates  from  the  blood  which  it  receives  by 
the  vessels  that  go  to  it.  1st.  On  the  head,  the  salivary, 
the  lachrymal,  the  Meibomeian  and  the  ceruminous  glands 
of  the  ear,  and  the  amygdalae.;  2d,  the  mammae  on  the 
thorax  ; 3d,  in  the  abdomen,  the  liver,  the  pancreas  and 
VOL  .III.  25 


194 


GLANDULAR  SYSTEM. 


the  kidneys  ; 4th,  in  the  pelvis,  the  prostate  and  the  testi- 
cles ; 5th,  on  the  wdiole  trunk  and  the  face,  the  very 
numerous  collection  of  mucous  glands  ; these  are  nearly 
all  that  are  dependant  upon  the  glandular  system ; all  the 
other  organs  which  belong  to  it  by  this  name,  are  foreign 
to  it  in  their  texture,  their  properties,  their  life  and  their 
functions.  In  this  point  of  view,  the  division  of  Vicq 
d’Azyr  is  inaccurate. 

The  extremities  contain  nothing  which  belong  to  this 
system,  no  doubt  because  the  fluids  which  it  separates 
almost  all  serve  for  the  functions  of  oi-ganic  life,  whilst  in 
the  extremities  every  thing  is  in  relation  to  animal  func- 
tions. 


ARTICLE  FIRST. 

SITUATION,  FORMS,  DIVISION,  &C.  OF  THE  GLANDULAR 
SYSTEM. 


The  glands  have  two  dijSerent  positions.  Some  of  them 
are  sub-cutaneous,  as  the  mammae,  the  salivary  glands,  &c. ; 
the  others  deep  seated,  as  the  liver,  the  kidneys,  the  pan- 
creas and  almost  all  the  mucous  ones  are  removed  from 
the  action  of  external  bodies.  The  greatest  number  oc- 
cupy  places  where  there  is  constantly  much  motion,  as 
the  salivary  glands  on  account  of  the  jaw,  the  mucous  on 
account  of  the  neighbouring  fleshy  layer,  the  liver  on  ac- 
count of  the  diaphragm,  &c.  It  is  this  which  has  made 
it  believed  that  this  motion,  foreign  to  their  functions, 
was  destined  to  produce  the  excretion  of  their  fluids. 


GLANDULAR  SYSTEM. 


195 


But,  1st,  the  glands  of  the  palatine  arch,  the  pancreas,  the 
testicles,  the  kidneys  even,  can  hardly  borrow  accessory 
aid  on  account  of  their  position.  2d.  We  know  that  the 
sight  alone  of  grateful  food  makes  the  saliva  flow.  3d. 
Sialagogues  produce  the  same  efiect.  4th.  When  the 
bladder  is  paralytic,  the  mucous  juices  pour  into  it  as  be- 
fore, oftentimes  more  copiously.  5th.  The  semen  flows 
involuntarily.  6th.  The  excretion  of  the  mucous  juices 
is  as  easy  in  the  pituitary  membrane  as  any  where  else, 
though  the  fleshy  layer,  almost  everywhere  spread  under 
the  mucous  system,  is  wholly  w'anting  here.  A thousand 
other  analogous  facts  prove  this  truth  placed  beyond  a 
doubt  by  Bordeu,  viz.  that  the  vital  action  is  the  essen- 
tial cause  of  every  excretion. 

Accessory  aid  should  not  however  be  entirely  rejected. 
In  fact,  in  salivary  fistulas,  there  is  evidently  more  fluid 
thrown  out  during  mastication  than  at  any  other  time.  It 
is  evident  that  in  the  excretion  of  urine,  the  abdominal 
muscles  perform  the  principal  part.  When  the  gall-blad- 
der is  emptied,  I believe  that  the  neighbouring  motions 
are  much  assistance  to  it.  In  general,  whenever  the 
fluids  are  found  in  considerable  quantities,  if  the  parietes 
of  the  organs  which  contain  them  are  not  very  strong, 
like  those  of  the  heart,  the  motions  of  the  neighbouring 
organs  are  necessary  to  overcome  the  resistance  which 
they  offer.  On  the  contrary,  in  the  capillary  vessels  in 
which  the  fluids  are  in  small  quantities,  the  organ  that 
contains  them  is  sufficient,  by  its  reaction,  for  the  motion. 

There  are  single  glands  like  the  liver-,  the  pancreas, 
&c.  ; and  others  in  pairs,  as  the  kidneys,  the  salivary, 
lachrymal  glands,  &c.  These  resemble  each  other  in  gen- 
eral on  both  sides ; but  their  resemblance  is  not  to  be 
compared  for  precision  to  that  of  the  organs  in  pairs  of 
animal  life.  One  of  the  kidneys  is  lower  than  the  other ; 
their  ai'teries,  veins  and  nerves  are  not  analogous  either 
in  length  or  size ; frequently  fissures  exist  in  one  that  are 


196 


GLANDULAR  SYSTEM. 


waniing  ill  the  other,  &c.  The  same  observation  is  true 
with  respect  to  the  salivary  glands. 

The  glandular  forms  are  not  fixed  and  invariable;  they 
exhibit  a thousand  different  modifications  in  their  size, 
direction  and  proportions  ; they  have  never  the  precise 
and  exact  conformation  of  the  organs  of  animal  life. 
This  fact  can  be  disputed  by  no  one  who  has  examined  a 
number  of  dead  bodies.  The  following  are  the  means 
by  which  I have  made  this  most  evident  to  myself.  We 
know  that  the  organs  vary  much  in  size,  in  different  in- 
dividuals ; now,  in  these  varieties  the  proportions  are 
always  accurately  kept  in  animal  life,  whilst  it  is  rare 
that  they  are  so  in  organic  life.  Let  us  take  an  organ  for 
example  in  each  of  the  two  lives.  I have  always  seen 
that  in  a small  brain  the  corpus  callosum,  the  thalami 
nervorum  opticorum,  the  corpora  striata,  &c.  are  in  pro- 
portion to  the  whole  size  of  the  organ.  On  the  contrary, 
nothing  is  more  common  than  to  see  a large  lobe  of  Spi- 
gelius  with  a small  liver,  and  vice  versa  a large  liver 
with  a small  lobe.  There  is  no  anatomist  who  has  not 
had  frequent  occasion  to  make  this  remarkable  observa- 
tion. A kidney  is  larger  sometimes  in  its  superior  part, 
sometimes  in  its  inferior,  &c.  It  is  in  the  whole  of  the 
organ  that  these  varieties  of  size  take  place  in  animal  life; 
it  is  oftentimes  in  insulated  parts  only  in  organic  life. 
The  reason  of  this  appears  to  me  to  be  that  the  harmony 
of  action  is  necessary,  as  I have  demonstrated,  for  the 
animal  functions ; so  that  if  one  side  of  the  brain  is  more 
developed  than  the  other,  if  one  eye,  one  ear,  one  pitui- 
tary membrane,  &c.  are  more  dev^eloped  than  their  cor- 
responding organs,  the  perception,  the  sight,  the  hearing, 
the  smell,  &c.  would  be  inevitably  deranged  ; whilst  the 
secretion  of  bile,  of  urine,  &c.  takes  place  equally  well, 
though  one  part  of  these  glands  may  be  larger  or  smaller 
than  the  other  parts. 


GLANDULAR  SYSTEM, 


197 


There  is  a remark  to  be  made  respecting  the  glands 
with  regard  to  these  varieties  of  form,  it  is,  that  those 
which  are  covered  by  a membrane,  as  the  liver,  the  kid- 
neys, even  the  pancreas,  are  less  exposed  to  them  than 
those  which  are  buried  in  cellular  texture  without  having 
around  them  a membranous  covering,  as  the  salivary,  the 
lachrymal,  the  mucous  glands,  &c.  I have  often  examin- 
ed these  last  in  the  mouth  and  in  the  course  of  the  trachea ; 
I never  found  them  alike  in  two  subjects.  We  know 
that  the  parotid  sometimes  extends  upon  the  masseter, 
and  sometimes  does  not,  that  it  descends  more  or  less 
into  the  neck,  that  it  is  of  a greater  or  less  size  there,  &c. 

When  one  gland  of  a pair  is  wanting  or  becomes 
diseased,  sometimes  the  other  increases  considerably  in 
size,  as  I have  seen  in  the  kidneys.  This  takes  place  also 
in  the  treatment  by  compression  of  salivary  fistulas,  a 
treatment  which  does  not  however  always  succeed.  In 
other  cases,  the  sound  gland  increases  its  action  and 
secretes  more  fluid,  without  increasing  in  size. 

The  exterior,  of  the  glands  not  covered  by  membranes 
is  unequal  and  lobulated  ; it  conforms  to  the  muscles,  the 
vessels,  the  nerves,  and  even  the  bones,  as  the  parotid 
w’hich  is  placed  under  the  angle  of  the  jaw.  Less  cellu- 
lar texture  is  in  general  found  around  them,  than  around 
organs  with  great  motion.  That  which  is  in  contact  with 
them  is  more  dense  and  compact  than  that  of  the  organic 
interstices.  It  closely  resembles  the  sub-mucous  texture, 
that  exterior  to  the  arteries,  the  veins,  the  excretories, 
&c.  but  it  is  not  however  so  resisting.  It  receives  fat 
with  difficulty,  and  forms  a kind  of  membrane,  which, 
insulating  to  a certain  extent  the  vitality  of  the  gland, 
performs  in  great  measure  in  this  respect  the  functions  of 
the  peritoneum  around  the  liver,  of  the  peculiar  mem- 
brane of  the  kidneys,  the  spleen,  &c. 


19S 


GLANDULAR  SYSTEM. 


ARTICLE  SECOND. 


ORGANIZATION  OP  THE  GLANDULAR  SYSTEM. 


I.  Texture  peculiar  to  the  Organization  of  this  Sys- 
tem. 

The  glandular  texture  is  distinct  from  most  of  the 
others  in  this,  that  the  fibrous  arrangement  is  wholly 
foreign  to  it.  The  elements  that  compose  it  are  not 
placed  at  the  side  of  each  other,  in  longitudinal  or  oblique 
lines,  as  in  the  muscles,  the  fibrous  bodies,  the  bones,  the 
nerves,  &c.  They  are  found  agglomerated,  united  by 
cellular  texture,  and  adhere  but  very  slightly.  Thus 
whilst  the  organs  with  distinct  fibres  resist  much,  espe- 
cially in  the  direction  of  their  fibres,  these  are  torn  with 
the  least  eflbrt,  and  break  even  with  ease.  Their  rup- 
ture is  unequal,  full  of  prominences  and  depressions,  a 
difierence  which  distinguishes  them  from  cartilage,  the 
rupture  of  which  is  in  general  smooth.  This  rupture  is 
not  equally  easy  in  all  the  glands.  The  prostate,  the 
amygdaliE,  the  mucous  glands  resist  much  more  than  the 
liver  or  the  kidneys,  which  principally  exhibit  this  phe- 
nomenon. The  pancreas  and  salivary  glands  yield  a little 
without  breaking,  when  they  are  pulled ; but  it  is  not 
their  texture  which  is  the  seat  of  this  phenomenon,  it  is 
the  abundant  cellular  texture  that  penetrates  them  ; thus 
their  different  lobes  are  then  separated,  in  proportion  as 
the  filaments  which  are  between  them  become  longer. 

The  glandular  texture,  which  is  very  cominonly  called 
parenchyma,  is  in  general  arranged  in  three  difierent 
ways.  1st.  In  the  pancreas,  the  salivary  and  lachrymal 


GLANDULAR  SYSTEM. 


199 


glands,  there  are  distinct  lobes,  separated  by  cellular  tex- 
ture, resulting  from  smaller  lobes  which  are  agglomerated 
together  and  which  are  composed  of  still  less  lobes,  that 
are  called  glandular  grains  ; the  scalpel  traces  with  ease  the 
first,  second,  third  and  even  fourth  divisions.  2d.  In  the 
liver  and  the  kidneys  there  is  found  no  trace  of  the  first 
of  these  divisions,  of  those  into  principal  and  even  secon- 
dary lobes.  The  glandular  grains  all  in  juxta-position, 
having  between  them  an  equal  quantity  of  cellular  tex- 
ture, a quantity  which  is  very  small,  as  we  shall  see,  pre- 
sent an  uniform  texture  without  inequality,  which  is 
broken  with  ease,  as  I have  said,  and  the  rupture  of 
which  exhibits  species  of  granulations.  3d.  The  pros- 
tate, the  amygdalae  and  all  the  mucous  glands  have  a soft 
parenchyma,  like  pulp,  without  the  appearance  of  prin- 
cipal or  secondary  lobes,  or  even  glandular  gi’ains,  not 
breaking,  yielding  much  more  under  the  finger  that  com- 
presses it,  than  that  of  the  other  glands.  The  simple  in- 
spection of  the  glandular  system  is  sufficient  to  enable 
an)^  one  to  perceive  the  triple  difference  which  I have 
just  pointed  out,  and  which  is  essential.  The  testicles 
and  the  mammse  have  a peculiar  texture  which  cannot  be 
referred  to  these  differences. 

Authors  have  been  much  occupied  with  the  intimate 
structure  of  the  glands.  Malpighi  admitted  that  there 
were  small  bodies  in  them,  which  he  believed  were  form- 
ed of  a peculiar  nature.  Ruysch  determined  that  they 
were  all  vascular.  Let  us  neglect  all  these  idle  questions, 
in  which  neither  inspection  nor  experiment  can  guide  us. 
Let  us  begin  to  study  anatomy  where  the  organs  can 
be  subjected  to  our  senses.  The  exact  progress  of  the 
sciences  in  this  age  is  not  accommodated  to  all  these 
hypotheses,  which  made  general  anatomy  and  physio- 
logy but  a frivolous  romance  in  the  last. 

There  is  no  doubt  that  the  excretories  communicate 
with  the  arteries  which  penetrate  the  glands.  Injections 


200 


GLANDULAR  SYSTEM. 


made  in  these  escape  with  great  ease  l)y  the  first,  with- 
out there  being  any  trace  of  extravasation  in  the  gland. 
The  blood  flows  often  naturally  by  the  excretories,  and 
produces  sometimes  bloody  urine,  saliva,  &c.  But  do 
tliese  facts  prove  that  there  are  only  vessels  in  the  glands, 
that  the  peculiar  parenchyma  of  which  they  are  the  re- 
sult does  not  depend  on  a substance  which  is  peculiar  to 
them  ? The  glands,  like  all  the  other  organs,  as  the 
muscles,  the  bones,  the  mucous  membranes,  &c.  have 
their  peculiar  texture  which  especially  characterizes  them, 
which  belongs  only  to  them,  a texture  in  which  the 
arteries  communicate  with  the  veins  and  the  excretories. 
Ljt  us  not  push  our  researches  further;  if  we  do,  we 
shall  be  inevitably  entangled  in  conjectures.  Let  us  con- 
iine ourselves  to  examining  what  phenomena  distinguish 
this  texture  from  all  the  others  wlien  subjected  to  the 
dllferent  reagents.  It  is  much  to  know  the  characteristic 
attributes  of  the  glandular  system,  without  seeking  to  un- 
derstand its  intimate  nature,  which,  like  that  of  all  the 
other  systems,  is  concealed  by  an  impenetrable  veil. 

The  glandular  parenchyma  dried  in  the  air  after  Iiav- 
ing  been  cut  in  slices,  loses  its  original  colour,  takes  a 
deep  one,  black  even  in  the  liver  and  the  kidneys,  in 
which  it  is  owing  especially  to  the  blood  Avhich  pene- 
trates these  glands,  since  if  they  are  dried  after  having 
Ijeen  deprived  of  it  by  repeated  washing,  they  remain 
grey  after  their  drying.  No  system  becomes  harder  or 
more  brittle  than  this  by  this  preparation.  It  diminishes 
then  less  in  size  than  most  of  the  others.  When  im- 
mersed in  water  after  being  thus  dried,  it  becomes  soft, 
resumes  in  part  its  original  appearance  and  its  tendency  to 
putrefaction,  which  takes  place  immediately  if  it  is  left 
in  the  open  air. 

The  glandular  texture,  when  exposed  to  the  air  so  that 
it  does  not  dr)^,  becomes  putrid  very  quickly,  and  gives 
out  an  odour  more  fetid  than  most  of  tlie  others.  More 


GLANDULAR  SYSTEM. 


201 


ammonia  appears  to  be  disengaged  from  it.  The  liver 
especially  produces  an  insupportable  odour  when  putrid. 
I do  not  know  any  organ,  kept  in  a vessel  full  of  water 
to  macerate,  which  gives  out  more  disagreeable  emana- 
tions. The  kidney  becomes  putrid  much  less  quickly ; 
this  varies  however  a little. 

When  boiled,  the  glandular  texture  furnishes  in  the 
first  moments  of  ebullition,  a great  quantity  of  grey  sub- 
stance, which  mixes  at  first  perfectly  with  the  water 
which  it  renders  turbid  and  then  collects  into  a copious 
scum  on  the  top  of  this  fluid.  It  is  this  texture,  the 
fleshy,  the  mucous  and  the  cellular  which  give  the  most 
scum  in  boiling,  as  it  is  the  cartilaginous,  the  tendinous, 
the  aponeurotic,  the  fibro-cartilaginous,  &c.  -which  give 
the  least  of  it.  It  should  not  be  believed,  moreover,  that 
this  first  product  of  stewing  is  uniform  in  its  nature  ; it 
varies  in  each  system  in  quality  as  well  as  quantity.  At 
least  I have  observed  that  its  appearance  is  never  the 
same,  that  it  has  nothing  constant  but  its  frothy  state, 
which  also  varies  much  and  which  is  even  almost  always 
nothing  in  the  mucous  system. 

The  liquor  which  results  from  the  boiling  is  very  much 
changed  in  colour,  and  ajipears  to  contain  many  more 
principles  than  that  made  with  the  white  organs.  An 
accurate  anal}*sis  of  the  liquor  in  which  each  system  had 
been  boiled  would  be  an  interesting  subject  of  research. 
I have  found  that  in  almost  all  the  appearance,  the  taste 
and  the  colour  were  different. 

The  glands  exhibit  a phenomenon  when  cooking  that 
especially  distinguishes  them.  They  harden  at  the  mo- 
ment of  the  first  ebullition,  and  acquire  the  horny  hard- 
ness like  all  the  other  systems ; but  whilst  most  of  these 
soften  again  from  long-continued  stewing,  so  as  to  become 
pulpy,  the  glands  uniformly  become  harder,  so  that  after 
five  or  six  hours  boiling,  they  are  three  or  four  times  as 
hard  as  they  naturally  are.  I have  very  often  made  this 
VOL.  III.  26 


202 


GLANDULAR  SYSTEM, 


experiment,  which  is  also  well  known  in  our  kitchens,  in 
which  when  a gland  is  cooked,  care  is  taken  that  the 
stewing  should  not  continue  too  long.  Beef  kidney 
finally  becomes  soft ; those  of  sheep  and  of  man  remain 
hard  for  a much  longer  time.  They  soften  however  more 
than  the  texture  of  the  liver,  which  is  of  all  the  glands 
that  which  exhibits  the  hardness  in  the  greatest  degree. 

Another  phenomenon  which  especially  distinguishes 
the  ebullition  of  the  glandular  system,  is  that  when  it  is 
taken  out  at  the  moment  it  has  undergone  the  sudden 
horny  hardening,  common  to  almost  all  the  animal  solids 
plunged  into  boiling  water,  it  has  not  like  the  others  ac- 
quired elasticity.  Draw  in  an  opposite  direction  a ten- 
don, a serous  or  mucous  membrane  or  a muscle  that  have 
undergone  the  horny  hardening,  they  stretch  and  after- 
wards suddenly  contract  the  instant  the  extension  ceases ; 
on  the  contrary,  a slice  of  liver  that  has  the  horny  hard- 
ness breaks  when  it  is  drawn  and  never  contracts.  The 
texture  of  the  prostate  appears  to  be  more  capable  of  then 
acquiring  a little  elasticity.  The  non-fibrous  disposi- 
tion of  the  glands  seems  to  have  much  influence  upon 
this  phenomenon. 

Exposed  to  the  sudden  action  of  a very  bright  fire  as 
in  roasting,  the  texture  of  the  liver  and  the  other  glands 
crisps  and  contracts  on  the  exterior.  There  results  from 
it  on  the  surface  a kind  of  covering  impermeable  in  part 
to  the  juices  contained  in  the  organ,  which  in  this  way 
becomes  cooked  in  these  juices  which  soften  it  in  the  in- 
terior, This  phenomenon  is  however  common  to  all  the 
solids.  Hence  why  care  is  taken  to  expose  what  is  roast- 
ing, whether  it  be  muscular  or  glandular,  at  first  to  the 
action  of  a very  quick  fire  ; afterwards  when  the  horny 
hardning  of  the  sui’face  has  been  produced,  it  is  diminish- 
ed, and  the  organ  is  cooked  with  a small  fire. 

The  glands  macerated  in  water  yield  differently  to  its 
action.  The  liver  resists  it  longer  than  the  kidney. 


GLANJ)ULAR  SYSTEM. 


203 


which  after  an  experiment  of  two  months  made  in  vessels 
placed  in  a cellar  has  been  reduced  to  a reddish  jelly 
swimming  in  the  Avater  ; whilst  the  first  preserved  for 
the  same  time  and  a little  longer,  its  form  and  density, 
and  had  only  changed  its  red  colour  to  a blueish  brown, 
whereas  the  kidney  retains  its  colour  in  maceration.  The 
salivary  glands  contain  much  of  this  Avhite,  unctuous  and 
hard  substance,  which  all  the  cellular  parts  when  long 
macerated  exhibit.  It  is  not  the  glandular  texture  that 
has  changed,  but  only  the  fat  contained  in  the  cellular 
texture,  which  is  here  very  abundant. 

The  acids  act  upon  the  glandular  texture  nearly  the 
same  as  upon  all  the  others.  They  reduce  them  to  a pulp 
which  varies  in  its  colour  and  the  rapidit}'  of  its  forma- 
tion, according  to  the  acid  employed.  The  sulphuric  is 
uniformly  the  most  efficacious  in  producing  this  pulp 
Avhich  it  blackens,  whilst  the  nitric  yellows  it.  All  the 
acids  act  with  much  more  difficulty  upon  the  glandular' 
texture  when  stewed,  than  when  raw.  My  experiments 
have  convinced  me  that  but  few  systems  exhibit  this  dif- 
ference in  a more  remarkable  manner. 

The  glands  are  much  less  digestible  than  many  other 
animal  substances,  especially  when  stewed,  which  pro- 
duces in  them  in  this  respect  an  effect  entirely  different 
from  what  it  does  in  the  cartilages,  the  tendons,  and  all 
the  fibrous  organs,  Avhich  by  it  lose  their  density,  be- 
come soft,  gelatinous,  viscid  even  and  are  easier  dissolved 
by  the  gastric  juice.  I believe  in  general  that  we  should 
digest  the  glands  much  easier  by  eating  them  raw. 
Every  one  knows  that  the  more  the  liver  is  cooked,  the 
more  indigestible  it  becomes.  This  induced  me  to  make 
a comparative  experiment  upon  this  organ  cooked  and 
raw  ; when  one  portion  in  the  second  state  Avas  reduced 
to  a pulp  in  the  stomach  of  a dog,  the  other  portion  in 
the  first  state  swalloAved  at  the  same  time  had  just  begun 
to  be  altered. 


204 


GLANDULAR  SYSTLM. 


Of  the  Exci'etories,  of  their  Origin,  of  their  Divi- 
sions, fyc.  Of  the  Glandular  Reservoirs. 

All  the  glands  have  ducts  destined  to  carry  off  the  fluid 
which  they  secrete  from  the  iriass  of  blood ; now  as  they 
are  only  found  in  the  glands,  they  should  be  considered 
with  the  peculiar  texture  of  these  organs.  The  origin 
of  these  ducts  is  uniform  in  all  the  glands.  They  arise, 
like  the  veins,  by  an  infinite  number  of  capillaries,  which 
form  the  last  ramifications  of  a kind  of  tree,  these  rami- 
fications appear  to  begin  at  each  glandular  grain,  where 
these  grains  exist ; so  that  for  each  there  is  one  of  these, 
an  artery  and  a vein.  Arising  thus  from  the  whole  of  the 
interior  of  the  gland,  these  ducts  soon  unite  and  form 
larger  ducts,  which  usually  go  in  a straight  line  though 
the  glandular  texture,  converge  towards  each  other,  unite 
with  other  ducts  still  larger  and  terminate  differently. 

In  respect  to  this  tei'mination,  glands  should  be  divid- 
ed into  three  classes.  1st.  Some  transmit  their  fluids  by 
many  ducts,  each  of  which  is  the  assemblage  of  smaller 
ducts,  opening  at  the  side  of  each  other,  but  all  entirely 
distinct  and  without  communication.  Sometimes  at  the 
place  where  these  ducts  terminate,  a more  or  less  con- 
siderable prominence  is  observed,  as  on  the  breast,  as  also 
on  the  prostate,  of  which  the  verumontanum  is  a kind  of 
nipple.  Sometimes  there  is  a depression,  a sort  of  cul- 
de-sac  which  is  found  at  the  place  of  these  orifices,  as  in 
the  amygdalae,  upon  the  tongue,  &c.  Sometimes  the  sur- 
face on  which  the  different  ducts  of  a gland  open,  is 
smooth  and  even,  as  is  the  case  with  that  on  which  those 
of  the  lachrymal,  sublingual  and  almost  all  the  mucous 
glands  open.  2d.  Other  glands  pour  out  their  fluid  by  a 
single  duct,  as  the  parotids,  the  pancreas,  the  sublinguals, 
&c.  ; this  arrangement  is  only  a modification  of  the  pre- 
ceding ; where  the  duct  opens,  no  inequality  is  usually 


GLANDULAR  SYSTEM. 


205 


discovered,  the  surface  is  smooth.  3d.  There  are  glands 
which,  before  throwing  out  their  fluid  by  their  excre- 
tories,  deposit  it  for  some  time  in  a reservoir  where  it 
remains  to  be  afterwards  expelled ; such  as  the  kidneys, 
the  liver,  the  testicles,  &c.  Here  there  are  always  two 
excretories,  one  which  goes  from  the  gland  to  the  reser- 
voir, the  other  from  the  reservoir  outwards.  These  re- 
servoirs are  evidently  a part  of  the  same  system  to  which 
their  excretory  ducts  belong. 

Though  the  first  and  second  species  of  glands  have  no 
reservoir,  yet  the  difi'erent  ramifications  of  their  excre- 
tories may  to  a certain  extent  be  considered  as  such.  In 
fact,  these  ramifications,  as  well  as  those  of  the  excre- 
tories of  the  glands  with  a reservoir,  are  constantly  full 
of  the  fluid  which  is  secreted  in  these  organs.  Whatever 
may  have  been  the  kind  of  death,  the  fluid  of  the  prostate 
may  be  always  made  to  ooze  out  by  compressing  the 
gland ; I have  often  even  by  pressure  produced  a very 
evident  jet.  The  papillae  of  the  kidney  also  uniformly 
give  out  urine  when  pressed.  The  liver  cut  in  slices 
allows  natural  bile  to  escape  from  the  divisions  of  the 
hepatic  duct.  The  semen  is  uniformly  found  in  the  wind- 
ings of  the  vas  deferens.  The  lactiferous  vessels  keep  the 
milk  in  their  cavitj”-,  till  it  is  evacuated,  and  it  has  even 
no  other  reservoir.  The  greater  or  less  size  of  the  mam- 
mae during  lactation  is  owing  to  the  greater  or  less  fulness 
of  these  vessels.  It  is  also  to  this  circumstance  that  must 
be  referred  the  peculiar  taste  of  each  glandular  texture, 
which  always  borrows  some  sapid  particles  from  the  fluid 
it  secretes.  We  know  that  the  kidney  has  always  an 
urinous  odour,  especially  in  old  animals.  It  is  to  this 
also  that  I refer  the  difference  of  putrefaction  which  I 
have  observed  between  this  organ  and  the  liver.  We 
know  that  the  bile  undergoes  putrid  fermentation  sooner 
than  the  urine  5 this,  when  it  is  veiy  acid,  can  even  pre- 
serve it  to  a certain  extent  from  putrefaction  ; expose 


206 


GLANDULAR  SYSTEM. 


then  the  liver  and  the  kidney  to  it,  the  latter  will  almost 
always  be  the  last  to  become  putrid,  as  I have  said. 

It  appears  in  general  that  the  course  of  the  fluids  in 
the  excretories  is  much  less  rapid  than  that  of  the  blood 
in  the  veins  and  even  than  that  of  the  lymph  in  the  ab- 
sorbents ; the  following  considerations  place  this  beyond 
a doubt.  The  urine  flows  continually  by  the  ureters,  as 
is  evidently  proved  by  fistulas  in  the  loins  ; now,  in  the 
time  taken  to  fill  the  bladder  by  this  uninterrupted  flow- 
ing, there  would  flow  from  a vein  of  a diameter  equal  to 
that  of  the  ureter  ten  times  as  much  blood,  and  much 
more  lymph  from  the  thoracic  duct.  Yet  this  rapidity  of 
motion  is  subject  to  many  varieties ; during  the  period  of 
inactivity  of  the  glands,  it  is  not  half  as  great  as  during 
their  activity  ; the  salivary  fistulas  are  a proof  of  this. 
We  know  how  promptly  the  ureters  transmit  the  urine 
from  the  drinks  that  are  taken. 

Size,  Direction  and  Termination  of  the  Excretories. 

The  size  of  the  excretories  varies.  1st.  Those  which 
go  out  in  considerable  number  from  a gland  are  very 
small,  often  hardly  perceptible.  They  commonly  run 
their  course  in  a straight  line,  do  not  anastomose  with 
each  other  and  open  immediately  upon  going  out  of  the 
gland.  2d.  Those  that  are  single  are  larger,  always  in 
proportion  to  the  size  of  their  gland,  except  however  the 
hepatic  which  is  evidently  very  small  in  comparison  with 
the  liver.  They  run  their  course  out  of  their  glands,  and 
arise  from  ducts  as  large  as  those  of  the  preceding  ones ; 
so  that  if  a single  trunk  arose  from  the  excretories  of 
these,  they  would  resemble  the  others  in  every  respect. 
They  differ  only  in  this,  that  their  secondary  excretories 
open  directly  on  their  surface,  whei-eas  they  unite  in  a 
common  trunk  in  the  others.  The  pancreas  is  the  only 
one  in  which  this  common  trunk,  goes  concealed  in  the 


GLANDULAR  SYSTEM. 


207 


gland  itself.  It  is  only  in  the  testicles  that  it  is  tortuous, 
and  in  which,  on  this  account,  it  is  longer  than  the  course 
which  it  has  to  run. 

Whatever  may  be  their  arrangement,  the  excretories 
pour  all  their  fluid  either  on  the  exterior,  as  the  urethra, 
and  ureters,  the  lactiferous  tubes,  and  the  ducts  of  the 
sebaceous  glands  ; or  on  the  interior  of  the  mucous  mem- 
branes, as  the  mucous,  salivary,  pancreatic,  prostate  and 
hepatic  excretories.  The  cutaneous  and  mucous  surfaces 
are  the  only  ones  then  on  which  the  excretories  termi- 
nate, the  only  ones  which  their  fluids  moisten.  These 
ducts  are  never  seen  opening  upon  the  serous  or  synovial 
surfaces.  The  excretories  of  the  pretended  articular  glands 
would  be,  if  they  existed,  an  exception  to  the  laws  of  the 
general  organization.  The  excretories  never  open  in  the 
cellular  texture  ; if  this  happens  preternaturally,  either 
abscesses  take  place  from  the  irritation  which  results  from 
it,  as  in  urinary  fistulas,  or  a callus  forms  in  the  course  of 
the  excreted  fluid,  and  thus  defend  the  cellular  system 
from  a troublesome  infiltration. 

Hence  the  mucous  tube  of  the  intestines  should  be  con- 
sidered as  a kind  of  general  excretory  added  to  the  pan- 
creatic, hepatic  excretories,  &c.  and  which  throws  out 
all  the  fluids  which  are  separately  poured  by  these  ducts 
into  it.  In  fact,  all  the  secreted  fluids  appear  to  be  des- 
tined, as  I have  said,  to  be  thrown  out  of  the  body. 
Separated  from  the  mass  of  blood,  they  are  foreign  to  it, 
and  do  not  enter  it  in  a natural  state.  Though  still  con- 
tained in  cavities  with  mucous  surfaces,  they  may  be 
truly  considered  as  being  out  of  our  parts.  These  sur- 
faces are  really  true  internal  integuments,  destined  to  de- 
fend the  organs  from  the  contact  of  the  substances  which 
they  contain,  a contact  which  would  inevitably  be  inju- 
rious to  them. 


20S 


GLANDULAR  SYSTEM. 


lieynarks  on  the  Secreted  Fluids. 

The  fact  that  the  secreted  fluids  are  destined  to  he 
thrown  out,  a fact  which  is  incontestable  with  regard  to 
the  urine,  the  bile  which  colours  the  excrements,  the 
saliva,  &c.  has  made  me  for  a long  lime  believe  that  the 
introduction  of  these  fluids  into  the  sanguineous  system, 
would  produce  the  most  serious  consequences.  I was  be- 
sides confirmed  in  this,  1st,  by  my  experiments,  in  which  I 
have  always  seen,  as  I have  said,  the  urine,  the  bile,  &c. 
injected  into  the  cellular  texture,  remain  without  being 
absorbed,  but  producing  abscesses ; 2d,  by  the  infiltra- 
tion of  the  urine  in  the  neighbourhood  of  the  bladder, 
from  which  abscesses  always  arise ; 3d,  by  the  serious 
consequences  from  the  effusions  of  this  fluid  in  the  perito- 
neum from  the  high  operation  for  the  stone,  and  of  the 
bile  on  the  same  surface  in  certain  penetrating  wounds, 
in  both  these  cases  these  fluids  never  re-enter  the  blood 
by  way  of  absorption,  like  the  peritoneal  serum,  but  almost 
al wsiys  occasion  death  j 4th,  by  an  experiment  in  which 
I had  seen  a dog  die  shortly  after  the  injection  of  urine 
into  the  jugular.  All  these  considerations  made  me  sus- 
pect that  the  secreted  fluids,  introduced  again  into  the 
mass  of  blood,  were  always  fatal  at  the  end  of  some  time, 
and  that,  as  some  physicians  whose  opinion  is  of  great 
weight  have  thought,  all  that  has  been  said  of  the  bile’s 
being  poured  into  the  blood  in  bilious  diseases,  is  but  a 
consequence  of  vague  ideas  of  the  reality  of  which  there  is 
no  proof.  Yet  the  importance  of  this  question,  in  regard 
to  medical  theories,  has  induced  me  to  resolve  it  by 
experiments,  so  as  to  leave  no  doubt  upon  the  subject. 

I have  then  injected  into  the  jugular  veins  of  many 
dogs  bile  taken  from  the  gall-bladder  of  other  dogs  which 
I opened  at  the  same  time.  For  the  first  few  days  they 
appeared  to  be  weary,  did  not  eat,  were  much  altered, 
their  eyes  were  heavy,  and  they  were  constantly  lying 


GLANDULAR  SYSTEM. 


209 


down  ; but  after  some  time  they  gradually  regainerl  their 
former  vigour.  I afterwards  enudoyed  human  bile  in 
these  experiments  •,  the  result  was  the  same,  except  that 
many  times  the  animal  had  hiccough  and  vomiting  some 
time  after  the  injection.  In  one  instance  a dog  died  in 
three  hours  after  the  experiment ; but  it  was  because  I 
made  use  of  that  extremely  black  fluid  that  is  sometimes 
found  in  the  gall-bladder  instead  of  bile  which  resembles 
thick  ink,  and  which  appears  to  form  a considerable  part 
of  those  black  vomitings  that  sometimes  take  place. 

These  experiments  induced  me  to  try  some  with  the 
saliva,  and  I obtained  the  same  result  from  them  ; only  the 
languid  state  that  succeeded  the  injection  was  less  evident. 
I afterwards  made  use  of  nasal  mucus  suspended  in  a 
sufficient  quantity  of  water,  for  it  can  hardly  be  dissolved 
in  it.  Finally  urine  itself  was  many  times  injected,  not 
that  which  comes  immediately  from  drink  and  is  only 
aqueous,  but  that  which  is  of  slow  formation.  In  this 
experiment  the  dogs  have  been  sicker,  but  only  one  died, 
and  that  happened  on  the  seventh  day.  I have  many 
times  repeated  it,  on  account  of  that  which  I performed 
three  years  ago ; the  same  result  has  alwaj  s taken  place, 
w'hich  makes  me  think  that  being  but  little  used  at  that 
time  to  make  experiments,  I introduced  by  accident  a 
bubble  of  air  through  the  syringe,  which  is  sufficient  to 
produce  the  death  of  the  animal. 

A question  then  is  evidently  settled  by  the  experiment. 
The  secreted  fluids,  though  destined  to  be  thrown  out  in 
the  natural  state,  can  re-enter  the  circulation,  without 
causing  the  death  of  the  animal,  which  is  only  more  or 
less  affected  according  to  the  nature  of  the  fluid  injected. 
Whether  the  bile  circulates  or  not  with  the  blood  in 
bilious  fevers,  I have  not  examined  ; but  it  certainly  can 
circulate  with  it  after  having  been  absorbed  in  its  canals. 
I do  not  doubt  but  that  in  purulent  reabsorptions,  the  pus 
VOL.  III.  27 


210 


GLANDULAR  SYSTEM. 


circulates  in  its  natural  state  in  the  sanguineous  system ; 
I confess  that  I have  not  made  experiments  upon  the 
injection  of  this  fluid,  but  I intend  to  immediately. 

We  exaggerate  every  thing.  No  doubt  the  solids  in 
which  the  vital  forces  are  especially  inherent,  are  particu- 
larly affected  in  diseases ; but  why  should  not  the  fluids 
be  aflfected  also  ? Why  should  we  not  seek  in  them  causes 
of  disease  as  well  as  in  the  solids  ? 

There  are  cases  in  which  these  are  primarily  affected, 
and  in  which  the  fluids  are  so  in  consequence  ; thus  in 
cancer,  in  the  affections  of  the  liver,  the  spleen,  &c.  in 
most  organic  lesions,  the  various  yellowish,  grey,  brown 
and  even  greenish  shades  of  the  face,  are  an  index  of  the 
consecutive  alterations  which  the  fluids  experience  in 
their  colour  and  consequently  in  their  nature. 

In  other  cases  the  affection  commences  with  them ; as 
when  the  venom  of  the  viper  is  introduced  into  the  blood, 
as  when  reabsorption  of  pus  takes  place  from  external 
abscesses,  or  in  phthisis,  and  as  when  there  is  absorption 
of  various  contagious  principles.  There  is  no  doubt  that 
the  different  substances  which  can  be  introduced  with  the 
chyle  into  the  blood,  may  be  the  cause  of  various  dis- 
eases. Is  it  not  the  blood  which  carries  to  the  brain  the 
narcotic  principles  which  produce  sleep?  does  it  not 
carry  turpentine  and  cantharides  to  the  kidneys,  mercury 
to  the  salivary  glands,  &c.  ? Inject  opium,  wine,  &c.  into 
the  veins,  and  you  will  stupify  the  animal  the  same  as  if 
you  had  given  them  by  the  stomach. 

Physiologists  at  one  time  were  much  engaged  with  the 
introduction  of  medicinal  infusions  into  the  veins  of  living 
animals.  They  circulated  by  these  infusions  purgatives, 
emetics  and  a thousand  other  foreign  substances,  the  con- 
tact of  which  the  blood  bore,  without  occasioning  any 
other  accident  to  the  animal  than  that  of  vomiting  or 
alvine  evacuations  if  they  were  emetics  or  purgatives,  and 
a greater  or  less  general  derangement  if  they  were  other 


GLANDULAR  SYSTEM. 


211 


foreign  substances  which  had  no  affinity  with  any  particu- 
lar organ. 

The  caustics,  as  the  nitric  and  sulphuric  acids  and  other 
very  irritating  substances,  have  alone  caused  death  in 
these  curious  experiments  of  which  Haller  has  given  us 
a sketch,  and  which  prove  that  various  substances  wholly 
foreign  to  the  blood  can  circulate  in  it,  and  that  it  is  a 
common  mass  in  which  are  found  many  principles  differ- 
ing from  each  other,  and  which  cannot  be  always  essen- 
tially the  same.  In  these  experiments  the  most  impor- 
tant part  has  been  neglected,  that  of  the  infusion  of  the 
different  animal  fluids,  particularly  the  secreted  ones,  and 
those  also  which  are  preternaturally  produced  in  diseases. 
I think  that  the  different  reabsorptions  would  be  much 
elucidated  by  the  infusion  of  the  various  kinds  of  pus, 
sanies,  &c.  But  we  have  already  sufficient  facts  to  con- 
vince us  that  the  fluids  and  especially  the  blood  can  be 
diseased  ; that  the  various  foreign  substances  mixed  with 
it  can  act  in  a fatal  manner  upon  the  solids.  In  fact,  every 
acrid,  irritating  matter,  without  being  mortal,  accelerates 
the  action  of  the  heart  and  produces  a true  fever,  if  inject- 
ed into  the  veins.  In  all  these  cases,  it  is  always  necessary 
that  the  solids  should  act ; for  all  the  morbid  phenomena 
suppose  their  alterations  ; but  the  principle  of  these  altera- 
tions is  in  the  fluids.  They  are  the  excitants,  and  the 
solids  the  organs  excited.  Now  if  there  are  no  excitants, 
there  is  no  excitement,  and  the  solids  remain  unaffected. 

Finally  there  are  cases  in  which  the  whole  economy 
both  solids  and  fluids  seem  to  be  simultaneously  affected ; 
such  are  adynamic  fevers,  in  which  at  the  same  time  that 
there  is  a general  prostration  of  the  first,  the  second  ap- 
pear to  be  really  decomposed. 

Let  us  not  exaggerate  then  medical  theories ; let  us 
regard  nature  in  diseases  as  she  is  in  a state  of  health,  in 
which  the  solids  elaborate  the  fluids  and  are  at  the  same 
time  excited  by  them.  There  is  a reciprocal  action, 


212 


GLANDULAR  SYSTEM. 


every  thing  succeeds  each  other,  every  thing  is  connected 
together.  Our  abstractions  hardly  ever  exist  in  nature. 
We  usually  adojDt  a certain  number  of  general  principles 
in  medicine,  and  we  accustom  ourselves  afterwards  to  de- 
duce from  these  principles,  as  necessary  consequences,  all 
the  explanations  of  diseases.  There  is  in  physical  phe- 
nomena a regularity  and  uniformity  which  never  deceive. 
In  morals  even,  there  is  a certain  number  of  principles 
achnowledged  by  all  men,  which  direct  them  and  regu- 
late their  actions  ; hence  a constant  uniformity  in  our 
manner  of  considering  moral  and  physical  phenomena; 
hence  the  habit  of  going  always  from  the  same  principles 
in  reasoning  upon  tliem.  We  have  carried  this  habit  into 
the  study  of  the  living  economy,  without  considering 
that  it  incessantly  varies  its  phenomena,  that  under  the 
same  circumstances  they  are  hardly  ever  the  same,  that 
they  are  continually  increased  and  diminished  and  have  a 
thousand  difi’erent  modifications.  Nature  seems  at  every 
instant  to  be  irregular,  capricious  and  inconsequent  in 
their  production,  because  the  essence  of  the  laws  which 
preside  over  these  phenomena,  is  not  the  same  as  that  of 
the  physical  laws. 

I wmuld  observe  that  the  experiments  the  result  of 
W'hich  I have  just  given  for  the  secreted  fluids,  differ 
from  those  tvhich  I published  the  last  year,  and  in  which 
these  fluids  have  always  been  fatal,  the  instant  they  were 
forced  towards  the  brain  by  the  carotid.  This  is  a phe- 
nomenon general  to  all  the  irritating  fluids,  wdiether  drawn 
from  the  economy,  or  foreign  to  it ; they  destroy  life 
when  they  arrive  at  the  cerebral  organ,  by  a direct  in- 
jection and  without  having  undergone  any  alteration, 
whilst  we  can  inject  them  with  impunity  into  the  veins, 
as  the  experiments  of  the  physicians  of  the  last  age  have 
proved.  We  can  even  without  danger,  as  I have  observ- 
ed, introduce  them  into  the  arterial  system,  on  the  side 
opposite  to  the  brain,  as  in  the  crui’al  artery,  for  example. 


GLANDULAR  SYSTEM. 


213 


Do  the  fluids  mixed  with  the  black  blood  rid  themselves 
of  some  principles  by  respiration,  before  they  arrive  at 
the  brain,  or  is  the  ])receding  phenomenon  owing  to  other 
causes  ? I know  not.  I would  only  observe  that  every 
thing  which  is  not  arterial  blood,  as  the  black  blood  and 
even  serum,  produces  death  when  forced  into  the  carotid. 
Water  alone  is  injected  with  impunity.  When  the  irri- 
tating principles  are  much  diluted  in  this  fluid,  their  con- 
tact is  less  injurious.  I have  seen  very  light  coloured 
urine  not  produce  death. 

Structure  of  the  Excretories. 

All  the  excretories  have  an  internal  membrane  which 
is  mucous,  and  which  is  a continuation  of  the  mucous  or 
cutaneous  surfaces,  upon  w’hich  they  terminate.  But  be- 
sides this,  they  all  exhibit  an  external  covering  which 
forms  the  shell,  as  it  were,  of  this  mucous  canal.  This 
shell  is  very  thick  in  the  vas  deferens,  in  which  it  ex- 
hibits a texture  but  little  known.  In  the  urethra  it  is 
of  a spongy  nature,  containing  much  blood  and  analogous 
to  the  glans  of  which  it  is  a continuation.  In  the  ureters, 
in  the  hepatic,  salivary  ducts,  &c.  it  is  this  extremely 
dense  and  compact  cellular  texture  of  which  we  have 
spoken,  which,  b)^  its  structure,  resembles  that  of  the 
arterial  and  venous  cellular  texture,  and  which  diflfers  es- 
sentially from  the  ordinary  cellular  texture,  as  from  the 
intennuscular.  It  does  not  appear  that  there  is  in  these 
ducts  a membrane  differing  from  this  dense  texture  and 
the  mucous  surface. 

Each  excretory  has  its  vessels.  The  ureters  evidently 
receive  branches  from  the  renal,  spermatic  arteries,  &c. 
&c.  The  hepatic  gives  them  to  the  ductus  choledochus  ; 
the  transverse  artery  of  the  face  supplies  the  duct  of  Steno. 
Various  nerves  coming  from  the  ganglions  accompany  the 
corresponding  arteries  and  veins.  Yet  I have  uniformly 


2M 


GLANDULAR  SYSTEM. 


observed  that  there  is  never  around  these  ducts  a plexus 
as  evident  as  there  is  around  most  of  the  arteries. 

The  excretories  have  principally  the  vital  properties 
of  the  mucous  system  which  forms  them  in  great  part. 
Their  sympathies  are  also  nearly  of  the  same  nature. 

II.  Parts  common  to  the  Organization  of  the  Glandu- 
lar System.  Cellular  Texture. 

The  glands  differ  much  in  the  cellular  texture  which 
enters  into  their  structure.  We  may  even,  in  this  respect, 
divide  them  into  two  classes. 

In  all  the  salivary  glands,  in  the  lachrymal,  in  the  pan- 
creas, in  all  the  glands  with  a granulated  and  white  paren- 
chyma, it  is  very  abundant.  Each  glandular  body  is  divid- 
ed into  lobes  very  distinctly  separated  by  grooves  which 
this  texture  fills,  and  which  produce  the  lobulated  appear- 
ance on  the  exterior  of  this  species  of  gland  ; not  only  each 
lobe,  but  each  lobule,  each  glandular  grain  even,  has  also 
the  cellular  texture  for  a boundary.  In  this  respect,  this 
sort  of  gland  is  truly  an  assemblage  of  small  distinct 
bodies,  which,  separated  from  each  other,  would  also 
perform  well  their  functions.  This  is  what  is  seen  in  the 
parotids,  in  which  different  accessory  glands  are  often 
found  in  the  course  of  the  duct  of  Steno,  and  are  perfect- 
ly independent  of  the  principal  gland.  Sometimes  there 
is  a continuity,  sometimes  there  is  a separation  between 
the  sub-maxillary  and  the  sub-lingual  glands.  The  cellu- 
lar texture  is  often  loaded  with  much  fat  in  this  species 
of  gland.  This  is  especially  remarkable  in  the  mammas, 
the  size  of  which  is  owing  sometimes  to  the  glandular 
texture,  as  in  young  people  in  whom  this  texture  predomi- 
nates over  the  fat ; sometimes  to  the  predominance  of  this 
fat,  as  we  see  after  the  fortieth  year,  when  this  gland 
preserves  a considerable  size.  The  difference  is  easily 
perceived  by  the  touch  by  the  softness  and  flaccidity  of 


GLANDULAR  SYSTEM. 


215 


the  organ  in  the  second  case,  and  by  its  resistance  and 
firmness  in  the  first.  In  the  age  of  puberty  often,  it  is 
also  the  fatty  cellular  texture  which  increases  the  size  of 
this  organ.  Hence  why  there  is  often  but  little  milk 
from  a large  breast,  and  a much  greater  quantity  from  a 
smaller  one.  In  the  voluptuous  sensations  which  we 
experience  at  the  sight  of  this  organ,  we  distinguish  very 
well,  without  being  conscious  of  it,  the  breast  whose  pro- 
minence is  real,  from  that  which  is  not,  and  in  which  the 
fat  only  raises  the  skin  of  the  breast.  It  is  rare  in  the 
salivary  glands,  the  pancreas,  &c.  that  the  cellular  texture 
predominates  so  much,  that  the  fat  accumulates  in  them 
in  so  considerable  a quantity.  I have  however  seen  cases 
in  which  the  parotid  resembled  a fatty  muscle ; but  there 
was  no  increase  of  size. 

In  the  testicle,  whose  parenchymatous  portions  arc 
separated  as  in  the  preceding  glands,  the  cellular  texture 
is  not  the  medium  of  union.  There  is  found  between 
each  grain  species  of  threads  which  appear  to  be  excre- 
tories,  and  not  real  cellular  laminae. 

In  the  glands  with  a compact  parenchyma,  as  the  liver, 
the  kidney,  the  prostate,  the  mucous  glands,  &c.  &c.  there 
is  very  little  cellular  texture  ; by  tearing  them  in  different 
directions,  they  break  without  exhibiting  intermediate 
laminae.  Fat  is  never  found  accumulated  in  their  paren- 
chyma. The  fatty  state  of  the  liver  which  takes  place  in 
many  diseases,  and  which  is  not,  as  has  been  thought,  an 
affection  necessarily  attendant  upon  phthisis,  exhibits  a 
phenomenon  wholly  different  from  the  mammae  and  the 
salivary  glands  when  they  have  become  fatty.  The  fat 
enters  then  like  an  element  into  the  texture  of  the  organ ; 
it  is  in  this  respect  like  the  colouring  substance,  whose 
place  it  has  as  it  were  taken ; it  is  not  found  in  cells. 
Moreover  much  of  it  can  be  extracted  by  ebullition,  and  I 
have  observed  that  much  of  it  swims  on  the  surface  of 
the  water  in  which  livers  of  this  kind  are  boiled.  The 


216 


GLANDULAR  SYSTEM. 


kidney  also  has  fat  in  its  interior;  but  it  is  around  the 
pelvis  and  not  in  its  peculiar  parenchyma.  The  amyg- 
dalae, the  prostate,  the  mucous  glands,  &c.  never  have  it. 
Serum  is  never  effused  into  the  texture  of  the  glands  with 
a compact  parenchyma.  The  most  complete  leucophleg- 
masia  leaves  them  sound  in  this  respect. 

Yet  it  cannot  be  doubted  that  the  cellular  texture  exists 
in  these  glands  ; maceration  demonstrates  it  in  them.  In 
the  fungous  tumours  that  grow  out  of  them,  there  is  much 
of  it.  It  is  principally  around  the  vessels  that  it  is  found  ; 
the  capsule  of  Glisson  is  an  example  of  this.  It  often 
happens  even,  as  I have  been  led  to  observe,  that  this 
texture  becomes  diseased,  whilst  that  of  the  gland  remains 
sound.  Thus  we  see  steatomatous  tumours  developed  in 
the  liver,  serous  cysts  in  the  kidney,  hydatids  in  both, 
and  various  productions  in  the  other  glands,  without 
deranging  the  secretion  in  the  least.  It  is  upon  the  liver 
especially  that  these  observations  are  best  made  ; its  size 
is  trebled,  even  often  quadrupled  by  internal  tumours, 
without  an  increase  of  its  texture ; this  texture  dilated 
forms  between  these  tumours,  species  of  partitions  in 
which  the  bile  is  secreted  as  usual.  The  same  thing  takes 
place  in  the  kidney,  in  which  serous  cysts  are  found. 
Sometimes  these  cysts  grow  there  till  the  whole  glandu- 
lar texture  is  destroyed,  and  there  remains  only  a large 
sac  separated  by  membranous  partitions,  and  filled  with 
serum.  I have  preserved  three  kidneys  of  this  kind. 

Blood  Vessels. 

All  the  glands  not  covered  by  a membrane,  receive  their 
arteries  from  all  sides.  Numei'ous  branches  coming  from 
the  neighbouring  vessels,  penetrate  the  whole  surface  of 
the  pancreas,  the  salivary  and  lachrymal  glands,  &c. 
These  arteries  wind  at  first  in  the  interstices  between  the 
lobes,  ramify  afterwards  between  the  smaller  lobes  and 
finally  penetrate  the  glandular  grains.  Each  of  them  has 


GLANDULAR  SYSTEM. 


217 


its  own  artery ; all  communicate  together ; so  that  those 
of  the  sub-maxillary  and  the  sub-lingual  are  filled  by  in- 
jection made  by  means  of  small  tubes  into  the  sub-mental, 
the  external  maxillary  or  the  lingual,  as  well  as  by  an  in- 
jection of  the  trunk  even  of  the  external  carotid. 

In  the  glands  surrounded  by  a membrane,  as  the  liver, 
the  kidney,  the  testicle,  &c.  the  arteries  enter  only  at  one 
side,  usually  in  a fissure,  and  by  a single  trunk  which  is 
very  considerable,  and  which  is  sometimes  divided  into 
many  branches  more  or  less  large.  This  part  of  the  gland 
in  which  the  artery  enters  is  always  the  most  distant  from 
the  action  of  external  bodies,  a remark  common  to  all  the 
important  organs,  as  the  lungs,  the  intestines,  the  spleen, 
&c.  which  ahvays  present  externally  their  convex  sur- 
face, that  on  which  the  vessels  are  the  most  ramified  ; so 
that  the  place  where  an  injury  can  happen  to  them  is 
that  where  hemorrhage  is  the  least  to  be  feared.  The 
principal  artery,  after  it  has  entered  the  gland,  is  soon 
divided  into  difierent  branches  which  separate  and  are 
subdivided  as  they  approach  the  convexity.  They  give 
off  in  their  course  many  branches  to  the  body  of  the  gland 
and  then  terminate  by  a great  number  of  capillaries  on 
the  convex  part  of  the  gland.  They  often  even  pierce 
the  organ  and  ramify  between  it  and  the  membrane  which 
covers  it.  For  example,  by  injecting  the  hepatic  artery, 
if  the  liver  is  bare,  many  small  blackish  stris  suddenly 
appear  on  its  convexity,  which  are  owing  to  this  cause. 
The  best  means  of  seeing  the  glandular  arterial  system, 
is  to  inject  a kidney  with  a solid  substance,  and  after- 
wards destroy  its  parenchyma  by  maceration  or  some- 
thing else.  The  arterial  system  is  then  bare  and  entirely 
by  itself.  Many  of  these  preparations  are  found  in  anato- 
mical museums. 

The  great  arterial  trunks  winding  in  the  glands,  com- 
municate to  them  an  internal  motion  very  favourable  to 
their  functions.  This  motion  is  so  much  the  more  evi- 
28 


VOL.  III. 


215 


GLANDULAR  SYSTEM. 


dent,  as  almost  all  these  organs  very  near  the  heart  by 
their  position  in  the  trunk,  are,  if  we  may  so  say,  under 
the  immediate  jar  of  its  contractions.  The  salivary  glands, 
the  mucous  ones  of  the  mouth  and  the  lachrymal  on  the 
one  hand,  the  testicle,  the  prostate  and  the  mucous  ones 
of  the  genital  parts  on  the  other,  exhibit  the  extremes  of 
this  position.  Another  cause  which  favoui’s  the  jar  of 
the  glands  by  the  entrance  of  the  blood,  is  that  almost  all 
,the  arteries  that  go  to  them  run  but  a very  short  course 
before  they  enter  them.  The  spermatic  alone  is  an  ex- 
ception to  this  rule  ; thus,  every  thing  in  the  secretion  of 
semen  seems  to  be  characterized  by  a remarkable  slow- 
ness. To  this  constant  motion  imparted  to  the  glands  by 
the  entrance  of  the  blood,  should  be  added  that  which  is 
communicated  to  them  by  the  neighbouring  organs,  and 
which  keeps  them  in  a constant  excitement,  which  is 
more  necessary  to  their  secretion  than  to  their  excretion. 
In  considering  the  action  of  organs,  the  constant  motions 
with  which  they  are  agitated  has  been  too  much  neglect- 
ed. The  example  of  the  brain  ought  however  to  fix  the 
attention  of  physiologists  upon  this  point. 

The  veins,  everywhere  continuous  with  the  arteries, 
follow  the  same  distribution  in  the  glandular  system,  and 
accompany  them  almost  everywhere.  We  do  not  see 
superficial  and  deep-seated  veins,  as  we  do  in  many  other 
organs.  The  liver  is  the  only  example  in  which  the 
red  blood  enters  at  one  side,  and  the  black  goes  out  at 
the  opposite. 

Most  of  the  veins  of  the  glandular  system  pour  their 
blood  into  the  general  system  of  black  blood,  and  as  many 
glands  are  very  near  the  heart,  they  feel  the  reflux  which 
this  system  often  experiences.  This  phenomenon  is  par- 
ticularly remarkable  in  the  liver,  as  the  hepatic  veins 
open  but  very  little  below  the  right  auricle.  Hence  why 
whenever  this  auricle  is  considerably  distended,  as  in 
asphyxia  and  in  death  in  which  the  lungs  being  crowded 


GLANDULAR  SYSTEM. 


219 


present  an  obstacle  to  the  blood,  the  liver  has  a much 
greater  quantity  than  usual.  I have  uniformly  made  this 
observation.  Weigh  comparatively  this  organ  when  the 
auricle  is  full  and  when  it  is  empty  in  the  dead  body, 
after  having  first  tied  all  its  vessels  ; you  will  find  a very 
great  difference.  For  the  same  reason,  you  will  observe 
a constant  relation  between  the  weight  of  the  liver  and 
that  of  the  lungs,  provided  a morbid  alteration  of  texture 
of  one  of  them  be  not  the  cause  of  death.  The  veins 
of  many  glands,  as  those  of  the  mucous  ones  of  the 
stomach  and  the  intestines,  as  those  of  the  prostate,  &c. 
pour  their  blood  into  the  system  of  abdominal  black 
blood.  There  are  hardly  any  in  the  system  of  which 
we  are  treating,  but  these  veins,  those  especially  of  the 
glands  situated  in  the  pelvis,  which  become  varicose. 
Varices  of  the  prostate  are  frequent,  as  we  know. 

Of  the  Blood  of  the  Glands. 

The  quantity  of  blood  that  is  constantly  found  in  the 
glands  varies  remarkably  ; they  may  even  be  divided  in 
this  respect  into  three  classes.  1st.  In  the  pancreas,  the 
salivary,  lachrymal  glands,  &c.  there  is  found  but  very 
little.  It  does  not  furnish  the  colouring  matter  to  these 
organs,  which  are  white,  and  wdiich,  when  macerated, 
tinge  with  red  but  two  or  three  waters.  2d.  In  the  mu- 
cous glands,  the  prostate,  the  testicles,  and  the  amygdalae, 
there  is  found  a little  more.  3d.  The  liver  and  the 
kidneys  contain  so  great  a quantity  of  it,  that  there  is  not 
in  this  respect  any  proportion  between  them  and  the  rest 
of  the  glandular  system.  This  is  owing  in  a small  degree 
in  the  first  to  the  cause  pointed  out  above  ; thus  it  often 
contains  more  than  the  second,  but  it  is  not  the  essential 
cause.  After  death  by  hemorrhage  in  which  there  was 
no  reflux,  in  the  liver  or  the  kidney  suddenly  taken  from 
a living  animal,  &c.  we  observe  the  same  thing.  In 
macerating  these  glands,  it  is  necessary  to  renew  the 


220 


GLANDULAR  SYSTEiM. 


water  at  least  a dozen  times  before  it  ceases  to  be  bloody. 
Hence  why  when  they  are  preserved  in  alkohol  on 
account  of  an  organic  disease  of  which  they  were  the 
seat,  they  must  be  first  macerated  for  a long  time ; if  not, 
the  liquor  soon  becomes  turbid  from  the  blood.  It  is 
this  quantity  of  blood  which  gives  to  these  glands  a 
greater  weight  in  proportion  than  that  of  the  other  parts. 
It  is  from  this  that  their  redness  is  derived,  a colour 
which  no  other  part  exhibits  to  the  same  degree,  but 
which  is  not  more  strongly  inherent  in  their  texture,  than 
it  is  in  the  mucous  surfaces  or  the  muscles.  In  fact,  we 
remove  it  with  the  same  ease  by  repeated  washing.  Then 
the  liver  assumes  a greyish  .appearance,  which  appears  to 
be  the  colour  inherent  in  its  texture,  as  white  is  that  of 
the  fleshy  fibre.  The  kidney  seems  a little  less  to  derive 
its  colour  from  the  blood.  It  remains  in  part  red  when 
macerated  ; the  pulp  even  which  is  the  product  of  it, 
after  remaining  some  months  in  water,  that  has  been  often 
changed,  still  exhibits  in  some  degree  this  colour,  much 
less  however  than  in  a natural  state. 

Does  the  state  of  the  secretions  make  the  quantity  of  the 
glandular  blood  vary  ? Does  more  of  this  fluid  enter  the 
kidney  when  it  furnishes  much  urine,  than  when  it 
secretes  but  little,  or  if  the  same  quantity  is  brought  by 
the  arteries,  is  less  returned  by  the  veins  in  the  first  than 
the  second  case  ? This  is  an  interesting  subject  for  expe- 
riment. 

Is  the  nature  of  the  blood  changed  when  it  arrives  at 
the  glands  ? Has  it  a peculiar  composition  before  enter- 
ing each  of  them  ? Much  has  been  said  of  this  change 
necessary  to  secretion  ; but  that  this  may  take  place,  there 
must  be  a cause  to  produce  it ; now  what  is  this  cause 
here  ? Does  not  the  blood  circulate  in  the  trunks  which 
go  to  the  glands,  as  in  the  others  ? It  would  be  necessary 
then  that  the  gland  should  be  surrounded  with  an  atmos- 
phere which  acts  upon  the  blood  at  a certain  distance 


GLANDULAR  SYSTEM, 


221 


from  the  place  where  it  is  ; a vague  idea,  which  has  no 
solid  foundation,  and  which  is  met  with  only  in  the  books 
of  those  who  have  never  made  experiments.  I have 
drawn  blood  from  the  carotid,  spermatic,  hepatic  and 
renal  arteries  ; it  is  equally  red  and  coagulable.  In  the 
same  animal,  it  is  impossible  for  the  senses  to  discover 
the  least  difference. 

I would  observe  that  secretion  differs  essentially  from 
nutrition  in  this,  that  it  always  draws  the  materials  of 
its  fluids  from  the  red  blood,  whereas  the  second  often 
takes  its  own  from  the  white  fluids,  as  we  see  in  the  ten- 
dons, the  cartilages,  the  hair,  &c. 

Nerves. 

The  glands  receive  two  species  of  nerves.  1st,  The 
cerebral  are  found  almost  exclusively  in  the  salivary  and 
lachrymal  glands,  the  amygdalae,  &c.  2d.  The  testicles, 

the  prostate  gland  and  the  liver  receive  them  in  an  al- 
most equal  proportion  from  the  brain  and  the  ganglions. 
3d.  The  kidneys  and  most  of  the  mucous  glands  receive 
scarcely  any  but  those  of  the  ganglions.  What  is  now 
said  of  the  nerves  should  be  understood  only  of  those 
that  are  free  and  independent  of  the  arteries  ; for  each 
arterial  trunk  that  enters  a gland,  is  surrounded  hy  a 
nervous  net-work  belonging  to  the  system  of  the  gan- 
glions, which  is  very  evident  in  the  great  glands,  as  in  the 
liver  and  the  kidneys  where  this  net-work  comes  from 
the  semilunar  ganglion,  in  the  salivary  glands  where  it 
comes  from  the  superior  cervical,  in  the  testicles  where 
it  comes  from  the  lumbar  ganglions,  &e. 

Compared  with  the  size  of  the  glands,  the  nerves  are 
in  small  proportion,  notwithstanding  what  Bordeu  has 
said.  It  is  not  necessary  in  fact  to  judge  of  this  propor- 
tion by  those  of  the  parotid  and  sub-maxillary  glands, 
which  merely  pass  through  these  glands  without  stopping 


222 


GLANDULAR  SYSTEM. 


in  them,  and  leave  only  some  branches  there.  For  ex- 
ample, there  is  certainly  no  organ  in  the  economy,  among 
those  which  receive  nerves,  that,  in  proportion  to  its  size, 
has  so  few  as  the  liver. 

Besides,  the  nerves  enter  the  glands  nearly  in  the  same 
way  as  the  blood-vessels,  that  is  so  say,  1st,  on  all  sides, 
in  those  that  have  no  membrane;  2d,  by  a groove  only  in 
those  that  are  covered  with  one.  They  divide  and  sub- 
divide after  entering  it,  and  are  soon  lost  sight  of.  Gan- 
glions never  exist  in  the  interior  of  the  glands. 

Have  the  nerves  an  influence  upon  secretion  ? It  is 
probable  they  have,  as  every  gland  is  provided  with 
them  ; but  they  by  no  means  exert  so  immediate  an  in- 
fluence upon  this  function  as  many  physicians  have  pre- 
tended. 1st.  It  is  said  that  the  nerves  of  the  parotid 
glands  have  been  cut,  and  that  the  secretion  of  the  saliva 
has  been  suppressed.  This  division  is  evidently  impossi- 
ble, since  the  gland  must  be  extirpated  before  removing 
its  nerves.  2d.  I have  divided  the  nerves  of  the  testicle 
of  a dog,  the  only  gland  in  which  this  experiment  can  be 
made.  I could  not  obtain  any  result,  because  an  inflam- 
mation of  the  gland  came  on  and  it  suppurated  ; but  this 
suppuration  even  supposes  that  the  nervous  influx  is  not 
actually  necessary  for  secretion,  since  suppuration  is  ac- 
complished by  a mechanism  analogous  to  that  of  this 
function.  All  physicians  know  that  a paralyzed  limb  can 
inflame  and  suppurate.  3d.  Erection  and  the  ejection  of 
semen  take  place  in  paralysis  of  the  lower  half  of  the 
body,  in  which  at  least  the  nerves  of  the  prostate  gland 
are  completely  paralyzed.  Mr.  Ivan  related  to  me  the 
case  of  a soldier  who  took  gonorrhoea  in  this  state.  4th. 
We  know  that  \vhen  tlie  bladder  is  perfectly  paralyzed 
and  its  nerves  have  no  longer  any  action,  its  mucous 
glands  still  continue  to  secrete  their  fluid  so  as  even  to 
produce  a catarrh.  5th.  The  nostril  of  the  affected  side 
in  hemiplegia  is  ss  moist  as  usual.  The  ear  of  this  side 


GLANDULAR  SYSTEM. 


223 


has  its  ordinary  quantity  of  wax.  6th.  In  paralysis  of 
the  uvula,  the  action  of  its  glands  continues.  7th. 
When  the  eighth  pair  of  one  side  of  a dog  is  cut,  the 
bronchia  is  found  some  days  after  to  contain  as  much 
mucus  as  common.  Sth.  During  the  convulsions  of  the 
different  parts  in  which  there  are  glands,  and  when  conse- 
quently the  nerves  of  these  glands  are  more  excited,  their 
secretion  is  not  increased.  9th.  If  we  weigh  the  proofs 
given  by  Bordeu  of  the  influence  of  the  nerves  on  secre- 
tions, we  shall  see,  that  they  either  rest  upon  false  facts, 
like  those  of  the  section  of  the  nerve,  of  sleep,  &c.  or 
upon  vague  data.  In  general  physicians  attach  no  pre- 
cise idea  to  the  term  nervous  influence  ; the  habit  of  ex- 
perimenting shows  how  much  they  have  abused  it.  When 
a nerve  being  cut,  paralyzed  or  irritated  in  any  manner, 
the  organ  which  receives  it  undergoes  no  derangement  in 
its  functions,  we  certainly  are  unable  to  appreciate  the 
nervous  influence  upon  this  organ.  I do  not  say  that 
it  does  not  exist,  but  I maintain  that  we  know  nothing 
about  it,  and  that  we  ought  not  to  employ  at  hazard  a 
word  to  which  we  cannot  attach  any  precise  idea.  What 
word  will  you  employ  then  to  express  the  influence  of 
the  nerves  upon  the  organs  of  the  senses,  upon  the  vol- 
untary muscles,  &c.  if  the  same  one  is  used  to  express  an 
action  which  has  no  relation  with  this,  and  which  per- 
haps even  does  not  exist  ? 

Exhalants  and  Msm'bents. 

This  kind  of  vessels  is  but  little  known  in  the  interior 
of  the  glands,  where  they  perform  only  the  purposes  of 
nutrition. 


S24 


GLANDULAR  SYSTEM, 


ARTICLE  THIRD. 


PROPERTIES  OP  THE  GLANDULAR  SYSTEM. 


I.  Properties  of  Texture. 


These  propei’ties  are  in  general  very  inconsiderable  in 
this  system,  which  appears  to  me  to  be  particularly  owing 
to  its  non-fibrous  texture.  In  fact,  in  order  to  be  elon- 
gated and  afterwards  contracted  and  preserve  their  integ- 
rity, it  is  necessary  that  the  particles  of  an  organ  should 
possess  a certain  degree  of  adhesion  and  cohesion  ; now, 
it  is  to  the  fibre  that  especially  belongs  this  double  attri- 
bute, Observe  also  that  the  glandular  system  is  sub- 
jected to  much  less  frequent  causes  of  distension  and 
contraction,  than  the  systems  with  distinct  fibres.  It 
is  scarcely  ever  found  distended  except  when  puru- 
lent deposits,  serous,  steatomatous  collections,  &c.  are 
formed  in  its  interior,  as  often  happens  in  the  middle  of 
the  liver,  kidney,  &c.  ; now  in  these  cases  it  does  not 
yield  like  the  skin,  the  muscles,  &c,  ; its  particles  are 
separated ; it  is  the  cellular  texture  with  which  they  are 
surrounded  that  is  uniformly  dilated  ; the  glandular  tex- 
ture is  even  soon  destroyed.  It  is  very  evident  when 
the  collections  are  formed  near  the  convexity  of  the 
glands  ; if  the  tumour  be  at  all  large  the  texture  of  the 
organ  disappears ; there  remains  only  a cellular  and  mem- 
branous cyst.  Hydatids  so  frequent  on  the  exterior  of 
the  kidneys  present  us  with  examples  of  it.  If  it  is  in 
the  middle  of  the  gland  that  the  cyst  is  formed,  the  de- 
struction also  takes  place,  but  it  is  much  less  evident. 


GLANDULAR  SYSTEM. 


225 


A strong  proof  of  the  small  degree  of  extensibility  of 
the  glands,  is  wdrat  takes  place  in  the  liver  in  dead  bodies. 
I have  said  above  that  it  is  more  or  less  loaded  with 
blood,  according  as  the  system  with  black  blood  had  been 
more  or  less  embarrassed  in  the  last  moments.  Now 
whatever  may  be  the  quantity  of  blood  it  contains,  its 
size  remains  nearly  the  same ; only  its  texture  is  more  or 
less  compressed  by  the  vessels,  whilst  on  the  contraiy 
the  greater  or  less  size  of  the  lungs,  which  is  very  appa- 
rent, always  indicates  its  state  of  fulness  or  vacuity.  It 
is  probable  even  that  it  is  this  difference  which  has  made 
all  physicians  neglect  the  infinitely  various  states  of  en- 
gorgment  in  which  the  liver  may  be  found  at  death, 
whilst  they  have  had  a particular  regard  to  the  A^arieties 
of  the  lungs. 

The  veins  of  the  kidneys,  further  from  the  heart,  are 
less  exposed  than  those  of  the  liver  to  the  reflux  that 
takes  place  in  the  last  moments  in  which  the  black  blood 
is  obstructed  in  the  lungs.  Yet  it  however  takes  place, 
and  we  see  very  great  varieties  in  the  quantity  of  blood 
in  the  great  renal  vessels,  a quantity  independent  of  that 
which  is  constantly  found  in  the  organ,  and  which,  as  I 
have  said,  is  very  considerable.  Now  the  size  of  the 
kidney  hardly  corresponds  to  these  varieties,  because  its 
extensibility  is  almost  nothing. 

As  to  the  glands  situated  at  the  two  extremities,  as  on 
the  one  hand  the  testicles,  and  on  the  other  the  salivary 
glands,  Ave  hardly  observe  in  them  the  sanguineous  stag- 
nation, because  the  reflux  is  not  sufficiently  evident.  We 
cannot  then,  in  this  way,  judge  but  by  analogy  of  their 
extensibility  and  contractility. 

Yet  the  engorgements  of  the  testicles,  consequent  upon 
gonorrhoea,  and  the  v'arious  swellings  of  the  parotid  glands 
proA'e  that  these  properties  exist  to  a certain  extent.  Are 
the  liver,  the  kidneys  and  other  internal  glands  subject  to 
those  acute  swellings  that  are  often  seen  in  the  sub-cuta- 
29 


VOL.  m. 


226 


GLANDULAR  SYSTEM. 


neous  ones  ? It  is  very  probable  ; perhaps  even  physicians 
have  not  paid  sufficient  regard  to  the  accessory  symptoms 
which  may  arise  for  a moment  from  the  pressure  of  these 
swelled  organs  on  the  neighbouring  parts.  Besides,  this 
swelling  and  the  contraction  that  follows  it,  may  take 
place  especially  in  the  cellular  texture  of  the  gland,  and 
consequently  suppose  less  extensibility  of  the  glandular 
texture  than  they  at  first  seem  to. 

11.  Vital  Properties.  Properties  of  Animal  Life. 

The  animal  contractility  is  evidently  nothing  in  the 
glandular  texture.  Does  the  sensibility  of  the  same  kind 
exist  in  it  ? The  following  facts  are  connected  with  this. 
1st.  A compression  of  the  parotid  is  to  a certain  degree 
painful.  I have  even  been  obliged,  in  a particular  case, 
to  give  up  the  method  of  compression  that  Desault  had 
advised  for  a salivary  fistula,  on  account  of  the  pain  the 
patient  experienced ; but  the  numerous  nerves  which 
traverse  this  gland  may  be  the  cause  of  these  pains. 
2d.  We  know  that  the  instant  the  lithotome  cuts  the 
prostate,  or  the  stone  and  forceps  pass  over  it,  the  patient 
suffers  very  much.  3d.  Stones  lodged  in  the  kidneys 
occasion  horrible  pains.  4th.  Any  considerable  pressure 
of  the  testicle  is  very  painful. 

On  the  other  hand  we  can  cut  the  texture  of  the  liver 
and  the  animal  will  give  no  signs  of  pain.  Haller,  after 
many  experiments,  ranked  the  glands  among  the  insen- 
sible parts.  What  is  to  be  concluded  from  this  ? That 
the  animal  sensibility,  modified  in  a thousand  ways,  ap- 
pears to  exist  in  many  organs  in  which  certain  agents 
cannot  put  it  in  action,  and  in  which  others  develop  it 
remarkably.  We  know  that  the  various  morbid  altera- 
tions render  it  very  evident  in  the  glands.  The  inflam- 
matory pain  of  these  organs  has  even  a peculiar  charac- 
ter ; it  is  obtuse  and  dull  in  the  greatest  number  of  cases. 


GLANDULAR  SYSTEM. 


227 


There  is  never  experienced  in  them  the  acute  sensation 
which  characterises  cellular  inflammation,  or  the  sharp 
and  biting  pain  of  which  the  skin  is  so  often  the  seat. 

Properties  of  Organic  Life. 

Of  the  properties  of  organic  life,  the  sensible  contrac- 
tility is  wanting  in  the  glandular  system.  But  the  two 
other  properties  are  developed  in  it  to  the  highest  degree. 
They  are  in  constant  activity  ; secretion,  excretion  and 
nutrition  keep  them  in  incessant  action  there.  It  is  by 
its  organic  sensibility  that  the  gland  distinguishes,  in  the 
mass  of  blood,  the  materials  which  are  proper  for  its 
secretion.  It  is  by  its  insensible  contractility,  or  its  tonic 
forces,  that  it  contracts  to  throw  out  those  which  are 
foreign  to  this  secretion.  The  first  is  on  a small  scale  in 
each  gland,  what  the  animal  sensibility  of  the  tongue  and 
the  nostrils  is  on  a large  one,  which  allows  only  aliments 
suitable  for  the  stomach  to  be  introduced  into  its  cavity  ; 
the  other  does  insensibly,  what  is  efiected  in  so  evident 
a manner  by  the  glottis,  when  it  rises  up  convulsively 
against  a foreign  body  that  attempts  to  enter  it.  The 
blood  contains  the  materials  of  all  the  secretions,  of  the 
nutrition  of  all  the  organs,  and  of  all  the  exhalations. 
Each  gland  draws  from  this  common  reservoir  what  is 
necessary  to  its  secretion,  as  each  organ  does  what  is 
proper  for  its  nutrition,  and  as  each  serous  surface  does 
what  is  suitable  for  its  exhalation.  Now  it  is  by  its  or- 
ganic sensibility  that  each  living  part  of  the  body  distin- 
guishes what  its  functions  require. 

When  the  fluids  enter  the  small  vessels  of  the  gland, 
this  sensibility  is  the  sentinel  that'gives  notice  of  it,  and  the 
insensible  contractility  is  the  agent  which  opens  or  closes 
the  gates  of  the  organ,  according  to  the  principles  that 
nre  presented.  This  comparison,  if  I may  be  allowed  the 
use  of  it,  gives  an  idea  of  what  then  takes  place.  Every 
glandular  action  turns  then  especially  upon  these  two 


22S 


GLANDULAR  SA'^STEM. 


properties,  and  as  this  action  is  almost  permanent,  they 
arc  then  constantly  in  exercise. 

From  tliis  it  is  evident,  that  all  the  glandular  diseases 
ought  to  suppose  a derangement  in  these  properties  ; for, 
as  we  have  often  seen,  they  are  the  predominant  properties 
of  an  organ,  those,  the  exercise  of  which  constitutes  its 
peculiar  life,  which  especially  determine  its  diseases,  by 
their  alteration.  This  is  in  fact  what  observation  shows  us. 
Here  we  see  these  properties  increased  or  diminished, 
sometimes  produce  an  increase  of  secretion,  as  in  diabetes, 
mercurial  salivation,  immoderate  flow  of  bile,  &c. ; some- 
times a diminution,  a suspension  even  of  this  function, 
as  in  acute  diseases  in  which  all  the  ducts  are  closed  as  it 
were  in  a moment,  as  in  the  suppression  of  urine,  dry- 
ness of  the  mouth,  &c.  It  is  the  alteration  in  the  nature 
of  the  glandular  sensibility  that  puts  it  in  relation  with 
fluids  foreign  to  the  glands  in  a natural  state  ; hence  the 
innumerable  varieties  of  the  secreted  fluids  especially  in 
diseases.  I have  spoken  of  these  varieties  as  it  regards 
the  mucous  fluids.  The  liver  and  the  kidneys  particu- 
larly do  not  experience  less  numerous  ones.  The  taste, 
the  colour,  the  consistence  and  odour  of  cystic  bile  ap- 
pear in  a thousand  different  states  in  dead  bodies.  Who 
is  ignorant  of  the  innumerable  alterations  of  which  the 
urine  is  susceptible?  The  saliv'a  is  less  variable;  but  in 
diseases  how  different  is  it  from  its  natural  state.  It  is 
sufficient  to  have  noticed  for  some  time  the  various  evacua- 
tions in  diseases,  to  see  of  how  many  modifications  they 
are  capable.  Nothing  less  resembles  the  urine  and  bile, 
than  the  fluids  sometimes  thrown  out  by  the  bladder  and 
the  liver;  whence  do  these  varieties  arise  ? From  this, 
that  the  variable  organic  sensibility  places  the  organ  in 
relation  with  substances  to  Avhich  it  was  foreign  in  a 
natural  state ; and  from  this,  that  the  insensible  contrac- 
tility allov/s  substances  to  enter  the  organ  which  it  be- 
fore excluded.  Tlie  same  gland  without  changing  its  tex- 

I 


GLANDULAR  SYSTEM. 


229 


ture,  by  a modification  only  of  its  vital  forces,  can  then 
be  a source  of  an  infinite  variety  of  different  fluids ; I be- 
lieve even  that  the  kidney,  by  taking  a sensibility  analo- 
gous to  that  of  the  liver,  may  secrete  bile.  Why  may  it 
not  secrete  it,  if  it  can  secrete  other  fluids  so  diflerent 
from  its  own  ? 

In  health,  each  gland  has  a mode  of  sensibility  nearly 
uniform,  a mode  which  changes  but  little ; thus  each 
secreted  fluid  has  an  appearance,  a consistence  and  a, 
nature  always  nearly  the  same.  But  in  diseases,  a thou- 
sand causes  change  this  mode  at  every  instant.  An  hyste- 
rical paroxysm  strikes  the  kidneys  ; in  an  instant  they 
repulse  all  the  pi’inciples  that  colour  the  urine,  and  this 
comes  out  limpid  ; the  paroxysm  passes  off,  the  organ 
resumes  its  ordinary  sensibilit}’’,  and  the  urine  returns  to 
its  usual  state.  The  influence  of  the  epileptic  parox)^sni 
extends  to  the  sensibility  of  the  salivary  glands  ; in  a 
moment,  a thick,  copious  and  frothy  saliva,  wholly  differ- 
ent from  the  natural,  comes  from  the  mouth ; after  the 
paroxysm,  the  sympathetic  storm  is  calmed  in  the  gland, 
and  the  saliva  returns  to  its  ordinary  state.  If  I may  be 
allowed  the  comparison,  the  glands  are  in  diseases  like 
the  atmosphere  in  the  equinoxes.  At  these  periods,  the 
winds  which  succeed  each  other  and  incessantly  change, 
often  make  rain,  hail  and  snow  succeed  each  other  in  a 
very  short  time  ; so  the  forces  of  the  glandular  life,  con- 
stantly variable  in  diseases,  make  the  different  products 
of  secretion  vary  with  rapidity. 

It  is  not  only  to  'secretion  that  the  various  alterations 
of  the  organic  sensibility  and  the  insensible  contractility 
of  the  glands  extend  ; these  alterations  when  long  con- 
tinued, have  an  influence  also  upon  their  nutrition  •,  they 
disturb  the  course  of  it;  hence  the  changes  of  texture, 
the  tumours  of  different  kinds,  the  organic  diseases,  &c. 
that  are  so  frequent  in  the  glandular  system,  a system 
which  presents  the  greatest  field  for  morbid  anatomy. 


230 


GLANDULAR  SYSTEM. 


The  great  nurnber  of  organic  diseases  which  it  exhibits, 
in  our  dissecting  rooms,  compared  with  most  of  the  other 
systems,  is  very  striking.  The  glandular,  the  cutaneous, 
the  mucous,  the  serous,  the  cellular  systems,  &c.  hold  the 
first  rank  in  this  respect.  Observe  also  that  it  is  in  them 
that  the  organic  sensibility  and  the  insensible  contractility 
are  raised  to  the  highest  degree,  because  they  are  the 
only  ones  in  which  these  properties  are  brought  into  action 
not  only  by  nutrition,  but  also  by  various  other  functions 
that  ai'e  going  on  in  the  insensible  capillary  system,  viz. 
by  exhalation,  absorption  and  secretion. 

Sympathies. 

Few  systems  are  more  frequently  the  seat  of  sympa- 
tliies  than  this.  In  examining  them  I shall  adopt  the 
same  order  as  in  the  preceding  system. 

Passive  Sympathies. 

The  glandular  texture  is  affected  with  extreme  ease  by 
all  the  others.  This  constitutes  its  passive  sympathies. 
They  take  place,  1st,  in  a natural  state;  2d,  in  diseases. 

I say  first  that  there  are  certain  cases  in  the  natural  state, 
in  which  the  other  organs  being  excited,  the  glandular  is 
brought  into  action.  This  is  especially  remarkable  in  the 
mucous  system.  We  have  seen  that  almost  all  the  ex- 
cretory ducts  terminate  upon  the  mucous  surfaces.  Now' 
when  one  of  these  surfaces  is  irritated  in  the  neighbour- 
hood of  an  excretory  duct,  the  gland  of  this  duct  in- 
cx'eases  its  action.  1st.  The  presence  of  aliments  in  the 
mouth  produces  an  abundant  flow  of  saliva.  2d.  A sound 
in  the  bladder,  irritating  the  ureters  or  their  neighbour- 
hood, increases  the  flow  of  urine.  3d.  The  h'ritation  of 
the  glans  penis  and  the  extremity  of  the  urethra  in  coition, 
produces  a kind  of  spasm  in  the  testicle  from  which  arises 
a copious  secretion  of  the  seminal  fluid.  4th.  Every 
irritating  fluid  applied  either  to  the  conjunctiva,  or  the 


GLANDULAR  SYSTEM. 


231 


pituitary  membrane  occasions  a more  or  less  considerable 
flow  of  tears.  5th.  'By  making  experiments  upon  the 
state  of  the  gastric  viscera  during  digestion  and  during 
hunger,  I have  observed  that  as  long  as  the  aliments  are 
only  in  the  stomach,  the  flow  of  bile  is  inconsiderable, 
but  that  this  flow  increases  when  they  pass  into  the  duo- 
denum, so  that  much  of  it  is  then  found  in  the  intestines. 
During  hunger,  the  gall-bladder  is  much  distended  ; but 
little  bile  flows  from  it.  At  the  end  or  even  during  diges- 
tion, it  contains  but  half  as  much  bile.  Yet  it  might  be 
emptied  much  more  easily  during  abstinence,  as  the  fluid 
which  is  then  found  in  it  is  of  a deep  green,  very  bitter, 
very  acrid  and  consequently  very  irritating.  On  the 
contrary,  during  or  immediately  after  digestion,  it  is 
much  milder,  of  a bright  yellow  and  less  irritating.  There 
must  then  be  another  stimulus  for  it  during  digestion ; 
this  stimulus  is  the  food  that  is  passing  by  the  extremity 
of  the  ductus  choledochus.  I have  pointed  out  in  a long 
note  in  my  Treatise  on  the  Membranes,  the  course  of  the 
cystic  and  hepatic  bile. 

Let  us  conclude  from  these  numerous  considerations, 
that  one  of  the  principal  means  which  nature  employs  to 
increase  the  action  of  the  glands,  and  to  produce  that  of 
the  excretory  ducts  is  the  sympathetic  irritation  of  the 
extremity  of  these  ducts  or  of  the  neighbourhood  of  the 
point  of  the  mucous  surface  where  they  come  out.  It  is 
to  this  also  that  must  be  referred  the  various  catarrhs  pro- 
duced by  an  irritating  body  remaining  upon  one  of  these 
surfaces.  The  infant  in  sucking  and  irritating  the  nipple, 
produces  a secretion  of  milk  at  the  same  time  that  he 
draws  it  out.  In  a morbid  state  the  glands  are  also  very 
frequently  the  seat  of  passive  sympathies.  It  is  almost 
always  then  the  organic  sensibility  and  the  insensible 
contractility  that  are  brought  into  action  in  them.  It 
is  rare,  that  the  animal  sensibility,  exched  by  sympa- 
thies, occasions  pains  in  the  glands. 


GLANDULAR  SYSTEM. 


o q.-) 

We  have  said  that  the  varieties  the  glands  exhibit  in 
diseases  are  innumerable,  either  as  it  respects  the  quantity 
or  the  quality  of  the  fluids  they  secrete.  Now  all  these 
varieties  are  especially  owing  to  sympathetic  influence. 
Observe  the  salivary  glands  moistening  the  mouth  or  leav- 
ing it  dry,  Ailing  it  with  a viscid  or  limpid  fluid,  frothy 
or  thin,  the  mucous  glands  of  the  tongue  furnishing  some- 
times a thick  whitish  substance,  and  sometimes  a black 
crust.  Physicians  consider  the  state  of  the  tongue  as  a 
constant  index  of  that  of  the  stomach ; this  is  most  often 
true.  Nature  has  established  such  a sympathetic  relation 
between  these  two  parts,  that  when  the  mucous  surface  of 
the  stomach  is  disordered,  and  is  the  seat  of  that  kind 
of  catarrh  which  is  called  derangement,  fulness  of  the 
stomach,  &c.  that  of  the  tongue  is  also  afiected  and  fur- 
nishes more  mucous  juices,  which  alter  and  destroy  the 
appetite,  and  thus  prevent  the  taking  of  aliments  which 
the  stomach  could  not  digest,  and  which  often  even  it 
would  not  bear.  The  tongue  is  then,  as  in  a state  of 
health,  a kind  of  sentinel  placed  over  the  stomach,  to  re- 
fuse that  which  would  injure,  and  to  admit  that  which  is 
suitable  for  it.  This  is  no  doubt  the  cause  of  this  singu- 
lar influence  which  the  stomach  exerts  upon  it  in  diseases. 
But  let  us  also  remark  that  sometimes  the  tongue  is  foul, 
^vhen  the  stomach  is  in  the  ordinary  state.  This  phe- 
nomenon is  frequent  in  hospitals  ; it  happens  to  me  very 
often.  And  vice  versa,  nausea,  &c.  sometimes  takes  place 
without  a catarrh  of  the  tongue. 

Shall  I speak  of  the  innumerable  influences  that  the 
liver,  the  kidney  and  the  jjancreas  receive  ? When  an 
organ  is  diseased  in  the  animal  economy,  these  immedi- 
ately perceive  it ; their  secretion  is  increased,  diminished 
or  altered,  and  oftentimes  even  the  sympathetic  affection 
does  not  extend  to  these  functions,  but  produces  inflam- 
mation, suppuration,  &c.  We  know  that  abscesses  are 
formed  in  the  liver  from  wounds  in  the  head,  &c.  Shall 


GLANDULAR  SYSTEM. 


233 


I speak  of  the  innumerable  varieties  of  the  flowing  of 
tears  in  acute  diseases,  in  inflammatory  and  malignant 
fevers,  &c.  } Who  does  not  know  that  the  eye  is  then 
more  or  less  moist,  that  it  is  often  constantly  weeping  ? 
Now  whence  arise  these  varieties?  fi'om  the  sympathelic 
influence  which  the  lachrymal  gland  receives.  The  dis- 
ease itself  is  often  foreign  to  it ; but  tbe  unknown  con- 
sensus which  connects  the  glands  with  the  diseased  parts, 
makes  them  then  enter  into  action.  We  weep  from  a 
variety  of  passions,  from  grief  especially  ; how  does  this 
happen  ? Because  the  influence  of  the  passion  is  first 
carried  to  the  epigastric  region,  as  the  violent  sensation 
experienced  there,  proves  ; and  the  affected  organ  reacts 
upon  the  lachrymal  gland.  We  weep  in  the  same  way 
as  we  sweat  from  fear,  or  spit  copiously  in  anger,  a phe- 
nomenon which  the  vulgar  express  by  these  words,  ybaw- 
mg  tviih  rage. 

The  testicles  and  the  prostate  are  much  less  often  sym- 
pathetically influenced  in  diseases  than  the  other  glands. 
Whilst  every  thing  is  disturbed  in  the  glandular  system, 
they  most  frequently  remain  calm  and  tranquil.  Why  ? 
because  they  are  insulated  by  their  functions  from  the 
other  glands.  The  salivary  glands,  the  pancreas,  the  kid- 
neys, the  liver  and  almost  all  the  mucous  glands  contri- 
bute to  one  common  object,  viz.  digestion.  This  object 
is  connected  with  the  existence  of  most  of  the  other 
organs.  When  these  are  diseased,  it  is  not  wonderful 
that  the  glands  feel  it.  On  the  contrary,  the  testicles, 
destined  only  to  the  purpose  of  generation,  entering  later 
into  action  and  ceasii:>g  to  act  sooner  than  the  other  glands, 
having  great  intermissions  in  their  action,  cannot  in  their 
affections  be  thus  connected  with  the  diseases  of  the  other 
organs.  Sometimes  however  they  are.  We  know  that 
some  affections  of  the  lungs  dispose  to  venereal  pleasures ; 
that  in  a natural  state,  alivel)^  excitement  of  certain  parts 
30 


VOL.  III. 


234 


GLANDULAR  SYSTEM. 


of  tlie  skin,  of  that  of  the  glutsei  muscles  especially  brings 
into  activity  the  whole  genital  system,  &c.  &c. 

We  know  the  remarkable  sympathy  that  renders  the 
mammae  dependant  upon  the  womb.  It  is  well  known, 
that  they  swell  a little  every  month,  at  the  beginning  of 
menstruation ; that  cancers  are  often  formed  in  them  at 
the  cessation  of  this  natural  discharge  ; that  the  voluptu- 
ous sensation  of  coition  sometimes  extends  even  to  them, 
&c.  All  physicians  have  observed  this  sympathetic  rela- 
tion which  appears  to  be  of  a peculiar  kind  and  to  depend 
upon  the  analogy  of  the  functions  of  the  sympathizing 
organs. 

After  severe  acute  diseases,  especially  idiopathic  fevers, 
the  glandular  action  is  oftentimes  much  increased  ; there 
are  great  evacuations  ; these  are  the  crises  ; it  is,  accord- 
ing to  the  opinions  of  most,  the  morbific  humour  that  is 
expelled.  This  is  a phenomenon  that  should  be  examin- 
ed, and  which  certainly  in  many  cases  does  not  depend, 
as  I shall  prove,  on  the  cause  to  which  it  has  been  attri- 
buted. 

Though  I consider  many  of  the  secretory  derangements 
in  diseases  as  sympathetic,  I am  far  from  thinking  that  all 
are  so.  Certainly  in  many  cases,  there  is  a general  affec- 
tion of  the  whole  system,  an  affection  in  which  the  glands, 
like  all  the  other  parts,  participate  ; this  is  w’hat  takes 
place  in  idiopathic  fevers.  But  when  one  system  is  espe- 
cially affected,  as  the  cutaneous  in  the  small  pox,  the 
measles,  scarlatina,  &c.  the  serous  in  pleurisy,  peritonitis, 
&c.  the  cellular  in  phlegmon,  the  nervous  in  convulsions, 
&c.  I call  the  derangement  whicli  the  others  experience 
sympathetic,  and  which  does  not  depend  upon  an  injury 
of  their  texture. 

Other  ideas  may  be  attached  to  the  word  sympathies, 
but  these  are  what  I have  connected  with  it  in  diseases. 
The  word  is  of  but  little  consequence,  provided  what  it 
expresses  is  understood. 


GLANDULAR  SYSTEM. 


235 


« 

Active  Sympathies. 

These  sympathies  are  less  frequent  than  the  preceding. 
In  the  diseases  of  the  glandular  system,  we  see  however 
examples  of  them.  The  history  of  inflammations  of  the 
kidneys,  the  salivary  glands,  the  liver,  &c.  shows  us  many 
phenomena  arising  sympathetically  in  the  other  systems 
on  account  of  the  diseases  of  this.  I do  not  speak  of  the 
derangement  of  digestion  and  the  circulation,  functions 
which,  naturally  connected  with  the  secretions,  are  inevi- 
tably^deranged  when  these  are ; I speak  of  the  organs, 
which  having  no  direct  relation  with  the  diseased  glands, 
are  yet  affected,  as  we  see  in  convulsions,  spasms,  wan- 
dering or  fixed  pains  in  different  places,  sweats,  &c. 

The  testicles  in  health  exert  a remarkable  influence 
upon  the  organs  of  the  voice.  We  know  that  it  becomes 
more  harsh  the  moment  they  enter  into  action,  and  that 
it  changes  when  they  are  removed  by  castration ; this 
phenomenon  is  constant  and  invariable.  Barthez  believed 
that  it  arose  from  the  ordinary  sympathetic  phenomena  ; 
in  fact,  it  appears  to  be  but  a particular  modification  of 
that  general  influence  which  the  testicles  exert  on  all  the 
vital  forces,  which  are  uniformly  debilitated  or  strength- 
ened, according  as  their  action  is  feeble  or  strong.  Yet 
some  organs  are  more  disposed  than  others  to  feel  these 
affections.  The  pectoral  mucous  system  is  an  example  of 
this.  Passive  hemorrhage  of  this  system  is  frequently 
the  consequence  of  excessive  excretion  of  semen  ; phthisis 
even  is  often  the  fatal  eflect  of  it. 

Characters  of  the  Vital  Properties.  First  Character. 

Life  peculiar  to  each  Gland. 

The  glandular  life,  the  result  of  the  preceding  forces 
considered  in  exercise,  is  not  uniform  in  the  whole  sys- 
tem, no  doubt  because  its  texture  differs  in  each  gland, 
and  because  to  each  texture  is  given  a peculiar  modifica- 


236 


GLANDULAR  SYSTEM. 


tion  of  vitality.  Many  phenomena  result  from  these 
differences  which  have  been  well  observed  by  Bordeu. 

1st.  Each  gland  has  certain  substances  with  which  it  is 
exclusively  in  relation  in  the  natural  state.  Hence  why 
the  salivary  glands  do  not  secrete  bile,  and  the  liver  allows 
the  materials  of  urine  to  pq^s  in  its  vessels  without  sepa- 
rating them  ; from  this  result^  the  diversity  of  secre- 
tions. Hence  also  why  cantharides  affect  exclusively  the 
kidneys ; why  mercury  acts  especially  upon  the  salivaiy 
glands  ; why  certain  substances  affect  the  testicles  in  a 
peculiar  manner,  increase  their  secretion  and  even  pro- 
mote the  excretion  of  the  semen  ; why  some  aliments 
give  more  milk  than  others.  I am  persuaded  that  cer- 
tain substances  act  upon  the  mucous  glands  and  dispose 
them  to  a greater  secretion. 

2d.  Each  gland  has  its  peculiar  mode  of  sympathies. 
We  have  seen  that  the  testicles  sympathize  especially  with 
the  pectoral  organs,  and  the  liver  with  the  brain.  The 
kidneys,  when  affected  with  acute  pain,  have  an  influence 
peculiarly  on  the  stomach,  and  occasion  vomiting.  The 
mammae  and  the  womb  are  directly  and  particularly  con- 
nected in  sympathies. 

3d.  The  inflammation  of  each  gland  has  a particular 
character.  That  of  the  kidneys  does  not  resemble  that 
of  the  liver,  the  testicles,  &c.  The  prostate  gland  when 
inflamed  produces  symptoms  wholly  different  from  those 
of  the  testicles,  &c.  I do  not  speak  of  the  differences 
resulting  from  the  diversity  of  the  fluids,  but  only  of 
those  which  arise  from  the  difference  of  texture. 

4th.  Each  gland  has  its  peculiar  diseases,  or  such  at 
least  to  which  it  is  disposed  more  than  the  others.  Hyda- 
tids are  very  often  found  near  the  convexity  of  the  liver  j 
they  are  never  seen  in  the  salivary  glands  or  the  testi- 
cles. Though  the  parotid  glands  are  as  much  exposed 
to  the  action  of  external  bodies  as  the  testicles,  there  are 
twenty  sarcoceles  to  one  scirrhus  of  these  glands.  The 


GLANDULAR  SYSTEM. 


237 


liver  alone  exhibits  that  peculiar  state  that  is  called  fatty  ; 
no  gland  is  more  frequently  the  seat  of  steatomatous 
tumours.  Physicians  who  have  opened  but  few  bodies, 
employ  the  vague  and  insignificant  word  ohstruction^ 
&e.  for  every  kind  of  glandular  swelling.  But  observe 
that  most  commonly  these  swellings  have  nothing  in  com- 
mon among  them  but  the  increase  in  size ; their  nature 
is  wholly  different,  and  yet  observe  how  ignorant  many 
are  in  medicine ; they  perceive  by  the  touch  that  there  is 
a hardness  of  the  liver,  and  immediately  aperients,  the 
acetate  of  potash,  &c.  are  the  common  means  which  they 
oppose  to  hydatids,  to  steatomatous  tumours,  to  scirrhi 
with  granulations  like  marble,  to  fatty  livers  and  to  a 
hundred  different  alterations  from  which  the  increase  of 
size  may  arise,  as  if  it  was  this  increase  and  not  the 
kind  of  tumour  that  produced  it,  which  they  had  to  com- 
bat. Give  then  also  aperients  when  the  liver  displaced 
by  hydrothorax  projects  unnaturally,  and  you  wnll  act 
almost  as  rationally. 

5th.  Each  gland  exhibits  peculiar  modifications  in  those 
evacuations  that  are  called  critical,  of  which  it  is  some- 
times the  seat  after  long  diseases,  &c.  &c. 

6th.  It  is  also  to  the  difference  of  vitality  of  the  dif- 
ferent parts  of  the  glandular  system,  that  ihust  be  referred 
the  following  phenomenon  ; certain  glands  enter  suddenly 
into  action,  either  from  a direct  irritation,  or  a sympa- 
thetic excitement,  as  the  lachrymal  for  example,  which 
from  a state  of  remission  passes  suddenly  from  the  influ- 
ence of  the  passions,  to  that  of  copious  secretion.  On 
the  contrary,  it  requires  some  time  to  excite  the  other 
glands,  as  for  example  the  kidneys,  pancreas,  &c.  which 
cannot  suddenly  pour  out  their  fluids,  whatever  may 
be  the  excitement  they  experience.  The  same  stimulus 
applied  to  the  conjunctiva,  produces  a flow  of  tears,  and 
at  the  same  time  increases  the  action  of  the  Meibomian 
glands ; but  the  first  effect  takes  place  before  the  other. 


238 


GLANDULAR  SYSTExM. 


The  same  stimuli  applied  to  the  mucous  surfaces  can 
never  produce  a catarrhal  discharge  till  the  expiration  of 
some  time. 

Second  Chay'acter.  Remission  of  the  Glandular  Life. 

The  second  character  of  the  glandular  life,  is  that  of 
being  subject  to  habitual  alternations  of  increase  and  dimi- 
nution. Sleep  extends  especially  to  the  animal  functions  ; 
they  alone  are  completely  suspended  in  the  ordinary  state, 
and  it  is  this  which  constitutes  sleep.  But  the  glands 
sleep  also  to  a certain  extent,  though  there  is  never  a 
complete  suspension  except  in  diseases.  I would  com- 
pare the  sleep  of  animal  life  to  the  intermissions  of  inter- 
mittent fevers  in  which  the  apyrexia  is  complete,  and  the 
sleep  of  the  glands  to  those  of  remitting  fevers  in  which 
the  paroxysm  is  only  moderated,  though  it  always  con- 
tinues. 

The  saliva  is  copiously  poured  out  when  aliments  enter 
the  mouth,  at  other  times  it  only  moistens  this  cavity. 
Whilst  the  chyme  is  passing  through  the  duodenum,  the 
pancreas  and  liver  moisten  it  abundantly  ; they  are  also 
in  action  during  hunger,  but  in  an  infinitely  less  degree. 
I have  convinced  myself  of  this  by  many  experiments 
upon  the  comparative  state  of  digestion  and  hunger,  the 
substance  of  these  experiments  I have  given  elsewhere. 
We  know  that  it  is  some  time  after  eating  before  the 
kidneys  commence  their  action.  The  intermissions  of 
the  action  of  the  mammae  are  almost  as  real  as  those  of 
the  organs  of  animal  life.  Each  mucous  gland  has  its 
time  of  secretion  ; it  is  that  in  which  the  surfaces,  to 
which  the  excretories  go,  are  in  contact  with  any  sub- 
stance that  is  remaining  there,  or  that  is  only  passing. 

The  glands  then  must  be  considered  as  continually  sep- 
arating a fluid  from  the  blood,  and  as  being  at  certain 
periods  in  greater  activity,  and  consequently  as  furnish- 
ing more  fluiejs. 


GLANDULAR  SYSTEM. 


239 


This  remission  of  the  glands  appears  to  be  owing  to  a 
cause  nearly  analogous  to  that  of  sleep,  which,  in  animal 
life,  is  produced  by  the  weariness  the  sensitive  and  loco- 
motive organs  experience,  after  long  continued  action. 
The  kind  of  weariness  which  the  glands  are  capable  of 
experiencing,  is  not  in  general  attended  with  a painful 
sensation,  as  in  animal  life ; its  nature  appears  to  be 
wholly  diflferent.  Yet  women,  after  nursing  too  long,  feel 
a pain  in  the  breast  that  warns  them  to  leave  off.  The 
testicles  become  the  seat  of  a painful  sensation,  when  the 
emission  of  semen  has  been  many  times  forced. 

Third  Character.  The  Glandular  Life  is  never  simul- 
taneously raised  in  the  whole  system. 

The  vital  properties  of  the  glands  are  never  simultane- 
ously excited  in  all.  When  one  is  in  action,  the  others 
are  in  remission.  We  might  say,  that  there  is  but  a de- 
terminate quantity  of  life  for  all,  and  that  one  cannot  live 
more  without  the  others  living  less.  To  this  law  is  the 
digestive  order  accommodated.  In  the  first  period  the 
salivary  glands  furnish  at  first  a great  quantity  of  fluid ; 
in  the  second,  the  parietes  of  the  stomach  ; in  the  third, 
in  which  the  chyme  passes  into  the  small  intestines,- 
the  liver  and  the  pancreas  are  principally  in  action  ; in 
the  fourth,  it  is  the  mucous  glands  of  the  great  intestines 
which  especially  act  j and  finally  the  kidneys  enter  into  a 
particular  action  in  order  to  evacuate  the  residue  of  the 
fluids.  All  the  glands  cannot  act  at  the  same  time ; it  is 
as  in  the  external  motions  in  which  certain  muscles  always 
rest  whilst  the  others  contract.  The  most  improper  time 
for  coition  is  that  of  digestion,  because  we  then  make 
the  mucous,  hepatic,  pancreatic  secretions,  &c.  coincide 
with  that  of  the  testicles.  In  diseases  one  gland  increases 
its  secretion  only  at  the  expense  of  the  others.  Observa- 
tion proves  this  every  day. 


240 


GLANDULAR  SYSTEM. 


We  might,  as  I have  said,  make  use  of  this  remark, 
by  producing  in  various  glandular  and  other  affections, 
artificial  catarrhs,  a disease  which  we  can  always  produce 
on  the  mucous  surfaces  by  the  introduction  of  a foreign 
body.  I have  for  some  time  past  made  much  use  of 
ammonia  respired  by  the  nose.  Pinel  prescribes  it  be- 
fore the  paroxysms  of  epilepsy.  There  are  an  infinite 
number  of  other  cases  in  which  it  is  very  cflicacious,  as 
in  some  kinds  of  cephalalgia,  in  ataxic  fevers,  in  certain 
apoplexies,  in  various  comatose  affections,  &c.  A blister 
does  not  act  till  the  expiration  of  some  time;  it  requires 
four,  five,  six  hours  even  for  it  to  produce  an  irritation. 
Who  does  not  know  that  oftentimes  in  diseases  in  which 
the  forces  are  much  prostrated,  it  has  no  action  on  the 
cutaneous  system?  On  the  contrary,  the  excitement  of 
the  pituitary  membrane  by  ammonia  is  always  sudden  on 
the  one  hand  and  always  efficacious  on  the  other.  Its 
effect,  it  is  true,  is  only  instantaneous,  but  this  is  pre- 
cisely its  advantage ; for  in  many  cases  a blister  is  only 
useful  the  moment  it  irritates  the  skin ; hence  the  use  of 
drying  it  immediately  and  reapplying  it.  The  employ- 
ment of  ammonia  or  of  any  other  strong  stimulant  upon 
the  pituitary  membrane,  can  be  repeated  every  quarter  of 
an  hour,  every  five  or  six  minutes  or  even  every  minute. 
If  habit  renders  the  patient  less  sensible  to  its  excite- 
ment, vve  can  replace  it  by  another  irritating  substance, 
whereas  we  cannot  thus  change  the  cutaneous  excitement 
by  a blister.  What  I have  said  of  the  pituitary  surface  is 
applicable  to  those  of  the  rectum,  the  urethra  and  stomach, 
on  which  we  can  in  many  cases  apply  in  diseases  excite- 
ments in  a more  advantageous  manner  than  is  done  upon 
the  skin  by  means  of  blisters. 

Moreover,  the  character  of  the  glandular  life  of  which 
we  are  treating,  is  only  an  insulated  modification  of  a 
character  general  to  all  the  vital  properties,  a character 
which  consists  in  this,  that  they  are  weakened  in  one 


GLANDULAR  SYSTEM, 


241 


place  when  they  are  raised  in  another.  Hence  why  the 
great  collections  of  pus,  large  tumours  and  dropsies  are 
always  attended  with  a weakness  in  the  glandular  action. 
It  is  upon  this  character  that  rests  the  use  of  vesicatories, 
setons,  moxa,  cauteries,  &c.  which  do  not  act,  as  has  been 
said,  by  evacuating  the  morbific  matter,  but  by  making 
the  irritation  of  the  diseased  part  cease  by  that  which  is 
produced  elsewhere. 

Fourth  Character.  In Jluence  of  climate  and  season, 
on  Glandular  Life. 

Another  phenomenon  is  also  derived  from  the  pre- 
ceding character,  and  it  is  one  that  may  be  likewise  con- 
sidered as  characteristic  of  the  glandular  system ; viz. 
that  in  general  it  is  in  greater  activity  in  winter  than 
summer,  in  cold  climates  than  in  warm.  In  fact,  heat 
which  expands  the  cutaneous  system  increases  the  action 
of  it  at  the  expense  of  that  of  the  glands,  and  recipro- 
cally cold  which  contracts  it,  by  preventing  the  constant 
exhalation  that  is  going  on  there,  forces  the  glandular 
system  to  supply  this  action.  Hence  why  the  same  fluid, 
introduced  into  the  economy,  goes  out  with  the  urine  in 
winter  and  with  the  sweat  in  summer  ; why,  if  we  wish 
to  produce  an  immediate  discharge  of  urine  in  summer, 
it  is  necessary  to  suppress  the  perspiration  by  the  sudden 
application  of  cold  to  the  surface  of  the  skin,  by  descend- 
ing into  a cellar,  or  some  other  subterraneous  place  ; so 
that  in  summer  we  can,  after  digestion,  make  the  product 
of  the  fluids  pass  off  with  the  urine  or  the  sweat,  accord- 
ing to  the  temperature  of  the  atmosphere  in  which  we 
digest ; why  teas  and  diuretics  forbid  the  use  of  each 
other,  and  why  a physician  who  should  employ  them  at 
the  same  time  would  know  but  little  of  the  laws  of  our 
economy ; why  most  of  the  diseases  that  are  attended 
with  an  immoderate  discharge  of  the  secreted  fluids,  are 
almost  always  characterized  by  a diminution  of  the  ex- 
VOL  .III,  31 


242 


GLANDULAR  SYSTEM. 


haled  fluids  ; why  in  some  seasons  diseases  have  a greater 
tendency  to  be  characterized  by  sweats,  and  in  others  by 
urinary,  mucous  evacuations,  &c.  It  is  to  the  greater 
degree  of  the  vital  activity  of  the  glandular  system  in 
the  winter,  that  must  then  be  referred  the  frequency  of 
catarrhs,  diseases  most  of  which  suppose  an  unnatural  in- 
crease of  its  action,  the  greater  facility  with  which  the 
kidneys  are  influenced  by  cantharides,  &c.  Physicians 
should  have  these  considerations  particularly  in  view  in 
their  treatment.  It  is  necessary  to  act  more  upon  the 
glandular  system  in  winter,  and  the  cutaneous  in  sum- 
mer, because  each  system  is  as  much  more  disposed  to 
answer  to  the  excitements  made  upon  it,  as  it  actually  is 
in  greater  activity. 

Fifth  Character.  Influence  of  Sex  upon  Glandular 

Life. 

Is  the  life  of  the  glandular  system  more  active  in  man 
than  in  woman  ? As  it  respects  the  glands  destined  to 
digestion,  the  secretion  of  the  tears,  the  evacuation  of 
urine,  &c.  there  is  but  little  difierence  in  the  two  sexes. 
As  to  genital  glands,  man  has  testicles  and  the  prostate  ; 
woman  has  mammae,  so  that  in  this  respect  they  seem  to 
be  equal.  Observe  however  that  the  influence  of  the 
first  upon  the  economy,  is  much  greater  than  that  of  the 
second.  It  is  from  the  womb  that  go  forth  in  woman 
the  irradiations  which  correspond  with  those  which  the 
testicles  send  to  all  the  other  organs. 


GLANDULAR  SYSTEM. 


243 


ARTICLE  FOURTH. 


DEVELOPMENT  OF  THE  GLANDULAR  SYSTEM. 


I.  State  of  this  System  in  the  Foetus. 


Though  the  secretions  are  not  active  in  the  foetus,  the 
glandular  system  is  in  general  much  developed.  All  the 
salivary  glands  and  the  pancreas  are  larger  in  propor- 
tion than  afterwards ; the  liver  is  enormous  ; and  the 
kidneys  have  a size  much  greater  in  proportion  than  they 
have  in  the  adult.  The  same  probably  is  true  of  the 
mucous  glands,  though  I have  not  made  any  very  pre- 
cise researches  upon  this  point.  The  form  is  different  in 
many;  the  kidney  for  example  is  evidently  uneven, 
whilst  afterwards  its  surface  is  almost  smooth.  The  colour 
is  not  the  same ; this  is  particularly  striking  in  the  salivary 
and  lachrymal  glands.  These  glands  which  are  white 
in  the  adult,  have  in  the  foetus  an  extreme  redness  which 
they  lose  by  washing,  which  is  not  owing  to  the  blood 
circulating  in  their  vessels,  though  there  is  much  of  it  in 
their  vessels,  but  it  is  really  inherent  in  their  texture. 
This  colour  is  never  as  great  in  the  pancreas,  though  its 
texture  is  nearly  the  same.  The  texture  of  the  glands 
is  extremely  soft  and  delicate  at  this  age,  which  is  the 
case  with  all  the  parts.  They  are  divided  and  yield  with 
great  ease,  and  their  vessels,  which  are  large,  carry  into 
them  a very  great  quantity  of  fluid. 

Then  they  are,  if  we  may  so  say,  in  a state  correspond- 
ing with  that  of  remission  in  the  adult ; they  secrete  even 
less  fluid,  though  they  appear  however  to  be  in  constant 


244 


GLANDULAR  SYSTEM. 


action.  In  fact,  all  the  reservoirs  would  be  insufficient 
to  contain  their  fluids,  if  in  a given  time,  as  much  flowed 
from  them  as  after  birth.  Is  this  because  the  black  blood, 
which  then  enters  their  parenchyma,  is  unfit  to  furnish 
the  materials  of  the  secretions  ? This  may  have  an  influ- 
ence, and  I have  elsewhei’e  imagined  it,  from  the  circum- 
stance that  this  blood  is  unable  to  support  many  other 
functions.  But  the  principal  reason  appears  to  me  to  be, 
that  in  the  foetus  the  nutritive  motion  of  composition  pre- 
dominates evidently  over  that  of  decomposition,  which 
is  very  inconsiderable.  Almost  every  thing  which  arrives 
in  the  organs  remains  in  them  and  continues  to  furnish  the 
materials  of  the  rapid  growth  which  is  then  taking  place  in 
the  body  ; now,  the  secretions  being  principally  destined 
to  carry  off  the  residue  of  nutrition,  must  then  be  very 
inactive. 

Besides,  digestion  does  not  introduce  into  the  blood  any 
of  those  principles  which,  being  useless  to  nutrition, 
must  on  this  account  go  out  as  they  entered,  that  is  to  say 
without  making  a part  of  our  organs ; such  are  for  exam- 
ple most  of  the  drinks,  which  only  pass  into  the  mass  of 
blood,  and  go  out  immediately  with  the  urine. 

The  glands  of  the  foetus  are  then  like  the  brain  at  that 
age  ; though  much  developed,  they  remain  inactive ; they 
are  in  the  expectation  of  action. 

II.  State  of  the  Glandular  System  during  Growth. 

At  birth,  the  glandular  system  increases  suddenly  in 
energy ; it  takes  a life  which  until  then  was  foreign  to 
it,  and  begins  to  pour  out  more  fluid.  It  owes  this  change, 
1st,  to  the  difference  of  the  blood  which  enters  it,  and 
which  till  then  black  and  consequently  venous,  then  be- 
comes red  and  charged  with  principles  that  are  new  to 
it ; 2d,  to  the  general  and  sudden  excitement  carried  to 
the  extremity  of  all  the  excretories,  by  the  aliments  to 
those  which  open  upon  the  canal  that  extends  from  the 


GLANDULAR  SYSTEM. 


245 


moutli  to  the  anus,  by  the  air  to  the  mucous  ducts  of  the 
bronchial  and  pituitary  surfaces  and  to  the  lachrymal 
gland,  by  the  various  frictions  of  the  extremity  of  the 
glans  penis  and  even  by  the  air  which  acts  also  upon  it, 
to  the  kidneys  and  the  bladder. 

All  the  glands  are  so  much  the  more  sensible  to  this 
sudden  excitement,  as  they  are  unaccustomed  to  it.  Their 
sensibility,  heretofore  torpid,  is  roused  ; they  feel  the 
contact  of  the  blood  which  enters  them  and  which  till 
then  had  made  only  a feeble  impression  upon  them. 
This  sensation  is  so  much  the  more  acute,  as  on  the  one 
hand  the  organic  sensibility  of  the  glands  becomes  more 
evident,  and  as  on  the  other  the  red  blood  is  a more 
powerful  stimulus  than  the  black  ; for,  as  I have  already 
had  occasion  to  observe,  the  blood  that  arrives  in  an  or- 
gan produces  two  effects  in  it,  one  of  which  is  to  excite 
it,  either  by  the  motion  it  communicates,  or  by  the  con- 
tact of  the  principles  it  contains,  and  the  other  is  to 
furnish  materials  for  the  different  functions,  as  for  exlia- 
lation,  secretion,  nutrition,  &c.  The  first  effect  is  com- 
mon to  all  the  organs  which  the  blood  enters ; the  second 
is  peculiar  to  each. 

I would  observe  however  that  many  of  the  secretions 
are  much  less  active  during  the  first  years,  than  they  are 
afterwards  ; such  are  those  of  the  salivary  glands,  the 
liver,  &c.  The  kidneys  being  destined  to  throw  out  the 
residue  of  digestion,  as  much  and  more  often  than  that  of 
nutrition,  are  in  a state  of  activity  in  proportion  to  that 
of  the  first  function.  The  infant  often  passes  urine,  as 
he  frequently  voids  excrements.  It  is  not  because  many 
substances,  returning  from  the  organs  which  they  have 
nourished,  present  themselves  to  the  kidneys,  to  be 
thrown  out  by  this  part. 

The  affections  of  the  glandular  system  are  not  the  pre- 
dominant ones  in  early  age.  1st.  It  is  not  the  parotids 
that  are  enlarged  in  the  frequent  swellings  that  take  place 


246 


GLANDULAR  SYSTEM. 


in  their  neighbourhood,  but  it  is  almost  always  the  lym- 
phatic glands.  2d.  We  know  that  an  excessive  flow  of 
bile,  and  the  affections  which  arise  from  it,  are  then  very 
rare.  3d.  All  the  secretions  relating  to  generation  are 
absolutely  nothing.  4th.  In  the  same  proportion  in  which 
the  organic  affections  of  the  liver  and  the  kidneys  are 
common  in  the  adult,  are  they  rare  in  the  infant.  Then 
it  is  in  what  are  improperly  called  lymphatic  glands,  in 
the  brain,  &c.  that  the  morbid  anatomist  finds  materials 
for  his  researches  ; for  observe  that  the  organs  which  are 
particularly  in  action  in  one  age,  are  those  which  are  most 
often  attacked  by  acute  and  chronic  diseases  at  that  age, 
and  that  on  the  contrary  they  seem  to  forget  those  in 
which  but  little  is  done.  5th.  Surgeons  know  that  sar- 
coceles,  hydroceles  by  effusion,  varicoceles  and  all  the 
diseases  of  the  testicles  are  as  rare  before  the  period  of 
puberty,  when  nutrition  only  is  going  on  in  these  glands, 
as  they  are  common  in  the  subsequent  years. 

It  appears  that  it  is  the  mucous  glands  which  are  then 
the  most  commonly  affected  and  are  consequently  in  the 
greatest  activity.  The  lachrymal  glands  are  also  very 
frequently  in  action.  The  infant  weeps  more  often  than 
the  adult  ; we  might  say  that  all  the  passions  which  agi- 
tate this  age  have  but  one  uniform  mode  of  expression, 
and  this  mode  is  weeping.  If  the  infant  suffers,  if  he  is 
jealous  or  frightened  he  weeps ; if  he  is  furious,  he  weeps 
because  he  is  not  very  strong.  This  influence  of  the  pas- 
sions upon  the  lachrymal  gland  in  the  early  years,  seems 
to  take  place  at  the  expense  of  the  influence  exerted  upon 
the  other  glands.  It  is  rare  that  fear  or  fright  give  to 
infants  a sudden  jaundice,  or  that  they  excite  bilious 
secretions.  At  this  age  they  do  not  pass  water  and  void 
their  excrements  from  fright  as  often  as  in  the  after  ages ; 
they  have  not  the  spasmodic  vomitings  that  are  so  fre- 
quently occasioned  by  the  passions  of  the  adult ; they  do 
not  become  pale  or  red  as  much  in  anger  ; thus  the  coun- 


GLANDULAR  SYSTEM. 


247 


tenance  is  not  to  the  same  extent  the  moveable  picture 
upon  which  is  painted  the  emotions  of  the  mind.  The 
eye  does  not  sparkle  in  anger  and  is  not  expressive  in 
friendship.  It  is  the  lachrymal  gland  which  then  most 
often  serves  in  the  face,  for  the  expression  of  the  passions. 
Observe  that  this  expression  is  that  of  weakness  and  want 
of  power,  it  is  that  of  w'oman,  who  resembles  the  infant 
in  so  many  phenomena.  The  feeble  stag  opposes  his  tears 
to  the  dogs,  who  seize  upon  him  to  devour  him. 

The  glandular  texture  remains  for  a long  time  soft  and 
delicate  in  the  infant.  At  birth  and  in  the  foetus,  neither 
the  liver  nor  the  .kidneys  have  the  singular  property  of 
hardening  by  boiling.  They  remain  during  this  experi- 
ment very  tender  and  yield  easily  to  the  least  impression. 
If  the  boiling  be  ever  so  long  continued,  they  do  not  lose 
this  character,  which  is  gradually  weakened  as  we  ad- 
vance in  age,  and  which  at  this  period  makes  the  glands 
fit  for  some  uses  in  our  kitchens  to  which  they  are  not  so 
proper  in  the  adult. 

III.  State  of  the  Glandular  System  after  Growth, 

Puberty  commences  about  the  period  that  growth  fin- 
ishes. A gland  till  then  inactive  in  man,  enters  suddenly 
into  activity.  The  prostate  follows  it  in  its  development. 
In  woman  the  breasts  swell,  separate,  and  acquire  in  a 
short  time  a size  which  they  would  not  have  done  in 
many  years,  if  they  had  grown  according  to  the  same 
laws  as  in  the  preceding  state.  The  other  glands,  far  from 
being  weakened,  in  proportion  as  these  become  strong- 
er, increase  their  action  also  ; they  become  stronger,  and 
gradually  lose  the  softness  that  characterized  them  in  in- 
fancy ; they  moreover  grow  harder. 

Till  then  composition  had  predominated  over  decompo- 
sition in  the  general  nutritive  motion.  Then  almost  as 
many  substances  are  constantly  thrown  from  each  organ, 


248 


GLANDULAR  SYSTEM, 


as  enter  its  interior  to  nourish  it.  Now  as  the  glands 
are  the  great  emunctories  which  throw  out  the  residue  of 
nutrition,  they  then  pour  out  more  fluids  in  proportion 
than  before. 

During  youth  it  is  the  genital  glands  which  predomi- 
nate over  the  others  ; they  seem  to  be  a centre  whence 
go  irradiations  that  animate  the  whole  machine.  We 
might  say  most  often  that  they  are,  in  the  mechanism  of 
our  moral  actions,  the  spring  which  puts  every  thing  in 
motion. 

As  we  recede  from  youth,  the  influence  of  the  genital 
glands  becomes  weaker,  because  they  are  in  less  activity. 
Towards  the  thirty-sixth  or  fortieth  year,  it  is  especially 
the  glands  destined  to  digestion  which  predominate  over 
the  others,  and  among  these  the  liver  in  particular  seems 
to  be  in  activity.  Then  the  bilious  aflections  are  predom- 
inant; then  the  passions  to  which  the  bilious  tempera- 
ment seems  to  dispose  us,  more  frequently  agitate  the 
mind.  Ambition,  hatred  and  jealousy  are  often  the  sad 
attendants  of  this  age.  These  passions  are  then  more 
durable.  The  levity  of  youth  and  the  passions  arising 
from  the  influence  of  the  genital  glands,  which  predomi- 
nate at  this  age,  had  for  a time  suppressed  these,  or  rather 
had  prevented  them  from  being  developed.  Then  they 
remain  alone,  the  others  having  escaped  in  smoke  with 
the  fire  of  youth.  Then  also  the  influence  of  the  lively 
emotions  of  the  mind  affects  especially  the  glands  and  the 
abdominal  viscera.  Then  is  felt  that  contraction  at  the 
epigastric  region,  the  painful  effect  of  the  bad  passions ; 
jaundice  occasioned  by  sorrow  is  then  more  frequent. 

This  age  is  that  of  the  organic  affections  of  the  glands, 
of  all  the  numerous  changes  of  texture,  of  all  the  ex- 
crescences which  destroying  as  it  were  the  nature  of  these 
organs,  transform  them  into  bodies  of  a different  texture. 
In  infancy,  leucophlegmasia  is  most  often  produced  by  an 
engorgement  of  those  lymphatic  bunches  that  are  called 


GLANDULAR  SYSTEM. 


249 


glands,  which  resembles  tabes  mesenterica,  the  engorge- 
ment of  the  bronchial  glands,  &c.  In  the  adult  on  the 
contrary,  it  is  with  the  diseases  of  the  liver,  of  the  spleen, 
of  the  kidneys,  that  it  is  most  often  seen. 

IV.  State  of  the  Glandular  System  in  Old  Jige. 

In  old  age,  the  glands  become  more  firm  and  hard. 
Before  that  period  even,  the  glandular  system  of  animals 
ceases  to  be  used  at  our  tables.  The  liver,  the  kidneys,  the 
spleen,  &c.  are  mixed  with  the  fleshy  texture  in  common 
boiled  meat,  only  to  communicate  to  it  some  salts,  some 
savoury  principles  that  are  foreign  to  this  texture.  They 
are  not  eaten,  or  at  least  they  are  not,  agreeable  to  the 
taste.  The  lungs  which  contain  so  great  a quantity  of 
mucous  glands,  do  not  atford  a very  digestible  aliment  ex- 
cept those  of  the  calf ; those  of  the  ox  are  not  brought 
to  our  tables,  especially  when  the  animal  is  old.  I would 
observe  upon  this  subject  that  the  muscular  and  glandular 
systems  are  in  an  inverse  order  as  it  respects  digestion, 
at  least  in  the  stewed  state  to  which  they  are  reduced  for 
nourishment.  In  fact,  the  glandular  system  has  not  an 
agreeable  taste  and  is  not  very  digestible  except  in  young 
animals,  whilst  at  this  age  the  muscular  is  insipid,  and 
does  not  become  savoury  food  till  towards  the  middle  of 
life. 

In  extreme  old  age,  the  colour  of  the  glands  changes 
less  than  that  of  most  of  the  other  organs.  We  find  the 
liver,  the  kidneys,  &c.  almost  as  full  of  blood  as  in  the 
adult ; they  are  as  red,  whilst  the  muscles  pale  and  colour- 
less announce  by  their  appearance  that  but  little  blood 
, enters  them  at  the  latter  periods  of  life.  We  might  say 
that  this  fluid  first  abandons  the  skin  and  the  muscles  of 
animal  life  which  in  the  trunk  are  subjacent  to  it,  and 
which  in  the  extremities  are  found  very  distant  from  the 
heart,  or  at  least  that  it  diminishes  much  in  the  two  sys- 
VOL.  III.  32 


250 


GLANDULAR  SYSTEM, 


terns,  and  is  concentrated  in  the  organs  in  the  neighbour- 
hood of  the  heart ; thus  the  secretions  are  still  very 
abundant  in  old  people,  whilst  the  muscular,  nervous 
forces,  &c.  are  considerably  weakened.  The  kidneys 
still  secrete  much  urine  ; the  liver  pours  out  much  bile, 
though  this  gland  loses  in  part  the  kind  of  predominance 
it  exercised  in  the  economy  towards  the  fortieth  year. 
We  know  that  the  very  frequent  catarrhs  that  then  take 
place,  indicate  an  increase  of  action  in  the  mucous  glands. 
The  functions  of  the  testicles  and  mammae  have  long 
since  ceased. 

The  activity  of  the  glands  remaining  in  exercise,  appears 
to  be  owing  to  two  causes.  1st.  The  decomposition  being 
very  great  at  this  age,  many  substances  are  presented  to 
the  glands  to  he  thrown  out.  An  old  person  decreases 
by  a phenomenon  opposite  to  the  rapid  growth  of  the 
foetus,  in  which  the  glandular  system  throws  out  scarcely 
any  thing  from  the  economy.  2d.  The  skin  having  the 
horny  hardness  and  being  contracted,  ceasing  in  part  to 
be  an  emunctory  of  the  products  of  decomposition,  the 
glands  supply  the  place  of  these  functions.  The  cutane- 
ous and  glandular  systems  are  then  in  the  same  relation 
as  in  winter  and  in  cold  countries,  in  which,  we  have 
seen,  that  the  second  constantly  supplies  the  place  of  the 
first. 

In  general,  the  glandular  system  is  one  of  those  in 
which  life  is  the  most  slowly  extinguished.  In  the  dead 
bodies  of  old  people  we  find  the  bile  still  filling  the  gall- 
bladder, the  bladder  full  of  urine,  &c.  All  the  glands 
when  compressed,  the  prostate  itself,  permit  a large 
quantity  of  fluid  to  escape  from  their  excretories.  I have 
even  observed  that  in  this  compression,  we  uniformly 
press  out  more  fluid  in  an  old  subject  than  in  a young 
one.  The  older  the  animals  are,  the  more  their  kidneys, 
as  we  know,  preserve  the  urinous  smell.  The  lungs, 
which  abound  so  much  in  mucous  surfaces  and  conse- 


GLANDULAR  SYSTEM. 


251 


quently  in  mucous  glands,  are  not  withered  and  have  not 
the  horny  hardening  in  old  age  ; they  perform  their  func- 
tions as  regularly  as  in  youth. 

In  general  it  is  a very  remarkable  phenomenon  that  all 
the  principal  internal  organs,  the  liver,  the  kidneys,  the 
spleen,  the  heart,  the  lungs,  &c.  still  preserve  a very  con- 
siderable vital  force,  whilst  the  sensitive  and  locomotive 
organs  already  almost  exhausted,  have  broken  in  part 
the  communications  which  connect  the  individual  with 
the  objects  which  surround  him. 


DERMOID  SYSTEM. 


ALL  animals  are  covered  with  a more  or  less  compact 
membrane,  of  a thickness  in  general  proportioned  to  the 
size  of  their  body,  destined  to  defend  the  subjacent  parts, 
to  carry  out  a considerable  portion  of  the  residue  of  nutri- 
tion and  digestion,  and  to  place  it  in  relation  with  ex- 
ternal bodies.  It  is  in  man  a sensitive  boundary,  placed 
at  the  extremity  of  the  domain  of  his  mind,  where  these 
bodies  continually  touch,  for  the  purpose  of  establishing 
the  relations  of  his  animal  life,  and  of  thus  connecting 
his  existence  with  that  of  every  thing  which  surrounds 
him.  This  covering  is  the  dermis  or  skin.  We  shall 
call  the  whole  of  it  the  Dermoid  System. 


ARTICLE  FIRST. 

FORMS  OF  THE  DERMOID  SYSTEM. 

The  covering  which  forms  this  system,  being  propor- 
tioned to  the  parts  that  it  covers,  is  applied  to  these  parts, 
adapted  to  their  great  inequalities,  and  allows  the  largest 
external  prominences  to  be  visible,  but  conceals  a great 


254 


DERMOID  SYSTEM. 


number  on  account  of  their  small  size  ; tlius  the  appeai-- 
ance  of  the  body  stripped  of  skin  differs  very  much  from 
that  with  the  skin  on. 

This  covering  everywhere  continuous  is  reflected 
through  diflerent  openings  in  the  interior  of  the  body 
and  goes  to  give  origin  to  the  mucous  system.  The 
limits  between  the  two  systems  are  always  marked  by  a 
reddish  line  ; within  this  line  is  the  mucous  system, 
without  it  the  dermoid.  Yet  the  demarcation  is  not  as 
striking  in  the  organization  as  in  the  colour.  Both  are 
confounded  in  an  insensible  manner.  In  the  neighbour- 
hood of  these  openings,  of  those  of  the  face  especially, 
the  dermoid  becomes  more  delicate.  At  the  commence- 
ment of  these  openings,  the  mucous  borrows  more  or 
less,  as  I have  said,  the  characters  of  the  first. 

I.  External  Surface  of  the  Dermoid  System. 

This  surface,  everywhere  contiguous  to  the  epidermis, 
is  remarkable  for  the  hairs  which  cover  it,  for  the  oily 
fluid  wliich  constantly  lubricates  it,  for  the  sweat  that  is 
deposited  on  it,  for  the  sense  of  feeling  of  which  it  is  the 
seat  and  which  the  internal  surface  does  not  possess.  We 
sliall  in  this  article  consider  only  the  external  dermoid 
forms,  without  regard  to  these  different  objects. 

Wc  see  upon  this  surface  different  kinds  of  folds. 

1st.  Some  are  owing  to  the  subjacent  muscles  which, 
being  intimately  connected  with  the  dermis,  forming 
almost  a part  of  it,  wrinkle  it  when  they  contract.  Such 
arc  the  wrinkles  on  the  forehead ; those  in  the  form  of 
rays  which  the  orbicularis  produces  around  the  eye-lids, 
&.C. ; those  of  which  the  cheeks  are  the  seat,  when  the 
great  and  small  zygomatic,  &c.  contract ; those  which  the 
orbicularis  of  the  lips  produces  around  the  mouth,  when 
it  contracts  it,  by  diminishing  its  opening,  &c.  All  these 
folds  are  owing  to  this,  that  on  the  one  hand  the  skin 
cannot  contract  like  the  muscles,  and  that  on  the  other  it 


DERMOID  SYSTEM. 


255 


is  necessary  that  it  should  occupy  less  space  in  length  at 
the  instant  these  are  shortened.  They  are  of  the  same 
nature  as  those  of  which  the  mucous  surfaces,  that  of  the 
stomach  in  particular,  become  the  seat  in  the  contraction 
of  the  fleshy  layer  which  is  contiguous  to  them.  Thus 
the  direction  of  these  folds  is  always  perpendicular  to 
that  of  the  subjacent  muscles  whose  fibres  they  cut  at  a 
right  angle.  We  are  accustomed  to  attach  much  impor- 
tance to  the  existence  of  these  wrinkles  in  the  expression 
of  the  passions  ; no  doubt  because  then  they  are  strongly 
marked.  In  fact  the  breadth  of  the  face  of  man  makes 
it  well  adapted  to  their  development,  whilst  that  of  ani- 
mals is  badly  formed  to  produce  them.  Thus  their  eye, 
rather  than  the  features  of  the  face,  is  the  moveable  pic- 
ture which  is  difierently  sketched  at  every  instant  by  the 
various  feelings  of  anger,  hatred,  jealousy,  &c.  The 
wrinkles  of  the  human  face  contribute  very  much  to  the 
expression  of  the  countenance,  they  compose  in  part  the 
physiognomy,  and  mark  its  different  shades. 

The  wrinkles  of  the  scrotum  are  analogous,  to  these  ; 
they  depend  upon  the  contraction  of  the  subjacent  cellu- 
lar texture,  in  which  some  ffeshy  fibres  appear  also  to  exist. 

2d,  There  are  other  wrinkles  which  are  owing  also  to 
the  motions,  but  not  to  those  of  the  subjacent  muscles. 
There  are  those  of  the  sole  of  the  foot,  and  especially 
those  of  the  palm  of  the  hand.  There  is  not  there  any 
sub-cutaneous  muscle  adhering  to  the  skin,  except  the 
small  palmar  muscle,  which  has  no  agency  in  these  wrin- 
kles that  are  formed  at  the  places  where  the  skin  is  con- 
stantly folded  in  flexion.  Thus  there  are  many  of  them 
about  all  the  articulations  of  the  phalanges.  In  the  palm 
of  the  hand,  we  see  three  principal  ones,  one  at  the  base 
of  the  thumb,  produced  by  the  motion  of  opposition, 
another  at  the  anterior  part  of  the  palm,  occasioned  by 
the  flexion  of  the  four  last  phalanges  which  are  bent  to- 
wards the  thumb,  and  the  third  is  found  in  the  middle  of 


256 


DERMOID  SYSTEM. 


the  palm.  The  dermis  is  folded  between  these  depressed 
lines,  in  the  motions  in  which  the  hand  is  hollowed. 
Many  other  small  folds  corresponding  with  less  evident 
and  less  frequent  motions,  cut  these  at  different  angles. 

On  the  back  of  the  foot  and  hand,  there  are  many 
wrinkles  about  each  articulation  of  the  phalanges,  when 
they  are  extended.  They  disappear  in  flexion,  and  are 
owing  to  this,  that  nature,  on  account  of  the  motions,  has 
made  the  skin  more  loose  at  this  place,  and  broader  in 
proportion  to  the  parts  it  covers.  About  most  of  the 
articulations,  there  are  analogous  folds,  but  they  are 
much  less  evident,  because  the  skin  adheres  less  to  the 
neighbouring  parts.  Upon  the  whole  trunk,  the  arm,  the 
fore-arm,  the  thigh  and  the  leg,  we  see  no  depressions  but 
those  from  the  muscular  prominences. 

3d.  There  is  a third  species  of  wrinkles,  or  rather  cu- 
taneous impressions,  which  are  not  very  evident,  found 
especially  on  the  sole  of  the  foot  and  the  palm  of  the 
hand  and  which  we  easily  distinguish  from  the  preceding ; 
they  are  those  which  indicate  the  rows  of  the  papillae. 
The  surface  of  the  trunk  presents  hardly  any  thing  similar. 

4th.  Finally,  there  are  the  wrinkles  of  old  age,  which 
are  of  a wholly  different  nature.  The  sub-cutaneous  fat 
having  in  part  disappeared,  the  skin  becomes  too  large 
for  the  parts  it  covers  ; now  as  it  has  lost  with  age  its 
contractility  of  texture,  it  does  not  contract,  but  folds  in 
various  directions.  Thus  where  there  was  the  most  fat, 
as  on  the  face,  these  wrinkles  are  the  most  evident,  they 
resemble  those  that  appear  on  the  abdomen  after  sevei'al 
pregnancies,  dropsy,  &c.  In  young  people,  if  emaciation 
takes  place  suddenly,  the  skin  contracts,  and  no  wrinkle 
is  formed. 

II.  Internal  Surface  of  the  Dermoid  System. 

This  surface  answers  everywhere  to  the  cellular  tex- 
ture which  is  loose  upon  the  trunk,  the  thighs,  the  arras, 


DERMOID  SYSTEM. 


257 


&c.  and  which  is  condensed  upon  the  cranium,  the  hand, 
&c.  In  most  animals,  a fleshy  layer  called  panniculus, 
and  of  a form  analogous  to  that  which  is  almost  every- 
where subjacent  to  the  mucous  system  of  man,  separates 
the  skin  from  the  other  parts,  and  communicates  to  it 
various  motions.  In  man,  the  dermoid  system  exhibits 
here  and  there  traces  of  this  internal  muscle,  as  is  ob- 
served in  the  platysma  myoides,  the  occipito-frontalis  and 
most  of  the  muscles  of  the  face.  There  is  nothing  simi- 
lar on  the  trunk,  extremities,  &c.  Man  is  as  much  infe- 
rior in  this  respect  to  most  animals,  as  he  is  superior  by 
the  arrangement  of  his  facial  muscles.  Thus  observe  that 
whilst  in  him  all  the  passions  are  painted  as  it  were  upon 
the  face,  and  the  whole  exterior  of  the  trunk  remains 
calm  in  these  tempests  of  the  mind,  this  exterior  is  con- 
vulsively agitated  in  animals.  The  mane  of  the  lion  be- 
comes erect,  the  whole  skin  of  the  horse  moves,  a thou- 
sand different  agitations  animate  the  exterior  of  the  trunk 
of  animals,  and  make  it  a general  picture  on  which  is 
painted  all  that  passes  in  the  interior.  You  can  deter- 
mine from  behind,  in  many  animals,  by  seeing  only  their 
bodies,  that  they  are  agitated  with  passion  ; cover  the  face 
of  man,  the  curtain  is  drawn  over  the  mirror  of  his  mind  ; 
thus  almost  all  nations  leave  it  uncovered.  The  phy- 
siognomy is  in  this  respect,  if  we  may  so  say,  more  gene- 
rally spread  over  the  exterior,  in  animals  with  a fleshy 
panniculus. 

Besides  the  cellular  texture,  the  dermis  is  almost  every- 
where subjacent  to  the  muscles  in  the  trunk ; but,  foreign 
to  the  motions  of  these  muscles,  it  receives  no  sensible 
influence  from  them.  In  the  extremities  it  is  found 
separated  from  the  fleshy  layers  by  aponeurotic  expan- 
sions. Many  vessels  wind  under  it ; the  great  veins  pass 
through  its  texture ; many  arterial  ramifications  go  upon 
its  surface,  and  many  nerves  between  these  ramifications. 

VOL.  in.  3.3 


258 


DERMOID  SYSTEM. 


ARTICLE  SECOND. 


ORGANIZATION  OP  THE  DERMOID  SYSTEM. 


I.  Texture  peculiar  to  this  Organization. 


This  texture  comprehends,  1st,  the  chorion ; 2d,  that 
which  is  called  the  reticular  body  ; 3d,  the  papillae.  The 
chorion  is  the  essential  part  of  the  dermis  ; it  is  that 
which  determines  its  thickness  and  form.  The  reticular 
body  appears  to  be  but  little  distinct  from  it.  The  papil- 
lae arise  from  it  also,  but  are  more  evident. 

Chorion. 

The  chorion  is  of  a very  variable  thickness.  1st.  In 
the  head,  that  of  the  cranium  and  that  of  the  face  exhibit 
an  opposite  arrangement.  The  first  is  very  thick  and 
also  dense  and  compact,  which  is  owing  especially  to  the 
numerous  hairs  that  go  through  it.  The  second,  every- 
where fine  and  delicate,  is  particularly  so  upon  the  eye- 
lids and  the  lips.  2d.  The  cliorion  of  the  trunk  is  poste- 
riorly and  all  along  the  back,  of  a thickness  almost  double 
that  of  its  anterior  part,  where  it  is  nearly  the  same  upon 
the  neck,  the  chest  and  the  abdomen.  I would  except 
however  that  of  tlie  penis,  tlie  scrotum,  the  great  labia 
and  the  mamime,  in  which  its  delieacy  is  greater  than  any 
where  else.  3d.  In  the  superior  extremities  it  is  nearly 
uniform  upon  the  shoulders,  the  arm  and  the  fore-arm  ; 
on  the  hand  it  increases  a little  in  tliickness  and  more  in 
the  palm  than  on  the  back.  4th.  This  thickness  is  gene- 
rally much  more  evident  on  the  thigh  and  the  leg,  where 


DERMOID  SYSTEM. 


259 


there  are  more  muscles,  than  on  the  arm  or  the  fore-arm. 

■ On  the  foot,  it  increases  as  on  the  hand,  less  in  the  doi’sal 
than  in  the  plantar  region,  which  is  the  thickest  of  all  the 
parts  of  the  dermoid  system  ; which  is  owing  principally 
in  the  natural  state  to  the  arrangement  of  its  epidermis. 
We  see  from  this,  that  though  everywhere  continuous, 
the  chorion  is  very  different  in  its  different  parts.  The 
relation  of  its  thickness  with  its  functions  is  easily  per- 
ceived on  the  hand,  the  foot,  the  cranium,  &c.  Elsewhere 
we  cannot  so  well  see  the  reason  of  these  differences, 
which  are  notwithstanding  as  constant. 

Woman  has  a chorion  generally  less  thick  than  that  of 
man  ; compared  in  all  the  regions,  it  exhibits  in  the  two 
sexes  a sensible  difference ; on  the  mammas  especially,  it 
is  much  more  delicate  in  woman.  That  of  the  great 
labia  however  is  proportionally  thicker  than  that  of  the 
scrotum. 

In  order  to  understand  perfectly  the  intimate  structure 
of  the  chorion,  it  is  necessary  to  examine  it  at  first  on  its 
internal  surface,  after  having  carefully  separated  it  from 
the  fatty  cellular  texture,  to  which  this  surface  adheres 
more  or  less  intimately.  We  see  then  that  it  is  differently 
arranged  according  to  the  regions. 

1st.  On  the  sole  of  the  foot  and  the  palm  of  the  hand, 
we  observe  an  infinite  number  of  rvhite  fibres,  shining 
like  aponeurotic  fibres,  which  are  detached  from  this  in- 
ternal surface,  form  upon  it  a kind  of  new  layer,  cross 
each  other  in  all  directions,  leave  between  them,  especial- 
ly towards  the  heel  many  spaces  of  different  sizes,  that 
are  filled  with  fat,  separate  more  and  more,  and  are  finally 
lost  in  the  sub-cutaneous  texture,  nearly  as  the  fibres  of 
the  brachial  aponeurosis  insensibly  disappear  in  the  neigh- 
bouring cellular  texture.  Hence  why  when  we  dissect 
the  palmar  and  plantar  integuments,  we  experience  the 
greatest  difficulty  in  separating  them  entirely  from  the 
cellular  texture  which  is  interlaced  with  these  fibres  ; 


260 


DERMOID  SYSTEM. 


hence  why  also  these  surfaces  have  not,  on  the  parts 
which  they  cover,  the  mobility  which  many  others 
exhibit. 

The  density  of  the  cellular  texture  contributes  also 
something  to  this  arrangement  which  is  essential  to  the 
functions  of  the  foot  and  the  hand,  which  are  designed  to 
seize  and  grasp  external  bodies. 

2d.  The  dermis  of  the  superior  and  inferior  extremi- 
ties of  the  back,  of  the  neck,  of  the  thorax,  of  the  abdo- 
men, of  the  face  even  and  consequently  of  almost  all  the 
body,  is  distinguished  from  the  preceding,  because  the 
fibres  are  much  less  distinct,  and  are  not  lost  in  the  cellu- 
lar texture  by  being  as  it  were  confounded  with  it,  whence 
arises  a remarkable  laxity  of  the  skin  of  these  parts,  and 
the  very  great  facility  with  which  it  is  dissected ; in  a 
word  because  the  spaces  between  these  fibres  are  much 
more  narrow.  These  spaces  appear  like  an  infinite  num- 
ber of  holes  irregularly  placed  at  tlie  side  of  each  other, 
containing  most  of  them  small  fatty  parcels  of  the  neigh- 
bouring texture,  and  exhibiting,  when  these  small  parcels 
have  been  carefully  removed,  very  evident  vacuities.  The 
fibres  which  form  them,  are  sufficiently  near  each  other, 
to  make  you  believe  at  first  view,  that  it  is  a surface 
pierced  with  an  infinite  number  of  holes,  that  has  been 
applied  under  the  skin.  On  the  contrary,  on  the  hand 
and  the  foot,  towards  the  heel  especially,  it  is  a true  net- 
work the  spaces  of  which  are  larger  than  the  fibres  that 
form  them  ; this  is  the  reverse  here.  Be  that  as  it  may, 
these  spaces  in  the  internal  surface  of  the  chorion  are 
very  favourable  to  the  action  of  tannin  which  penetrates 
Ihe  texture  infinitely  better  from  this  side  than  from  the 
opposite,  because  it  insinuates  itself  into  these  numerous 
openings.  I have  had  occasion  to  observe  it  in  the  human 
chorion  which  I have  had  tanned  for  the  purpose.  Chap- 
tal  has  observed  that  the  epidermis  is  a real  obstacle  to 
tlie  action  of  tannin,  and  that  on  this  account  scraping  is 


DERMOID  SYSTEM. 


261 


a preliminary  operation  essential  to  tanning,  since  it  allows 
the  skin  to  be  penetrated  on  both  sides  ; but  even  when 
thus  scraped,  it  receives  the  tannin  much  more  easily  on 
the  side  of  the  flesh  than  on  the  opposite  one. 

3d.  The  chorion  of  the  back  of  the  hand  and  the  foot, 
as  well  as  that  of  the  forehead  does  not  exhibit  these 
numerous  openings  on  its  internal  surface ; it  is  smooth 
and  white,  especially  when  it  has  been  macerated  a little. 
It  is  precisely  the  same  as  that  of  the  scrotum,  the  pre- 
puce and  even  the  great  labia.  The  texture  of  it  is  more 
compact,  no  space  is  left  in  it,  so  that  though  more  deli- 
cate than  that  of  the  extremities  and  the  trunk,  it  con- 
tains almost  as  much  substance.  As  to  the  chorion  corres- 
ponding to  the  hair  and  the  beard,  we  see  in  it  only  the 
openings  necessary  for  the  passage  of  the  hairs,  and  which 
are  wholly  different  from  those  of  which  I spoke  just 
now,  which  form  real  culs-de-sac,  and  do  not  pierce 
through  the  chorion. 

Hence  the  internal  face  of  the  dermoid  chorion  exhibits 
three  very  distinct  modifications.  The  first  and  last  are 
seen  to  a small  extent,  whilst  the  second  is  almost  gene- 
ral, with  some  differences  however  in  the  trunk,  the  ex- 
tremities and  the  head.  Besides,  these  modifications  do 
not  suppose  a diversity  of  nature,  but  only  of-  forms. 
Much  separated  and  arranged  in  fibres  in  the  first,  the 
dermoid  texture  is  compact  and  condensed  a little  in  the 
second,  and  by  this  condensation  renders  the  spaces  less 
distinct.  But  there  is  a means  of  seeing  them  every- 
where very  well,  where  there  is  the  least  trace  of  them, 
and  this  is  by  maceration.  This  means  also  shows  the 
dermoid  texture  best.  In  fact,  when  the  skin  has  re- 
mained for  some  time  in  water,  it  softens,  the  fibres  of 
its  chorion  separate,  and  their  interstices  become  more 
distinct ; then  we  see  that  the  spaces  exist  not  only  on 
the  internal  surface,  but  that  they  extend  into  its  texture 
which  appears  to  be  truly  like  a sieve  in  its  whole  thick- 


262 


DERMOID  SYSTEM. 


ness,  so  numerous  are  the  sjjaces  arising  from  tlie  inter- 
lacing of  the  fibres. 

These  spaces  do  not  terminate  in  culs-de-sac  towards 
the  external  surface  ; they  open  upon  this  surface  by  many 
foramina  which  are  very  evident  in  a skin  that  has  been 
macerated  for  a month  or  two,  and  which,  in  the  ordinary 
state  are  almost  imperceptible  in  some  subjects,  and  very 
visible  in  others.  Besides,  in  order  to  see  them  it  is 
necessary  to  remove  the  epidermis ; now  as  with  the 
view  of  producing  this  effect  immediately  we  commonly 
employ  the  action  of  boiling  water  or  fire,  the  dermoid 
texture  by  this  means  acquires  the  horny  hardening,  and 
they  become  much  less  apparent,  whereas  maceration  not 
only  does  not  produce  horny  hardening  of  the  skin,  but 
it  expands  and  dilates  it,  which  renders  these  foramina 
very  evident.  In  some  parts  of  the  skin  and  in  certain 
subjects,  we  might  then  introduce  the  head  of  a pin  into 
them  ; in  others  they  are  less  evident.  These  foramina 
never  pierce  the  dermis  perpendicularly,  all  open  ob- 
liquely to  its  surface  ; so  that  a perpendicular  pressure 
tends  to  close  them  and  bring  their  parietes  in  contact. 
1 cannot  compare  their  termination  better  than  to  that  of 
the  ureters  in  the  bladder ; hence  why  the  hairs  which 
go  through  them  are  never  perpendicular,  but  oblique  to 
the  skin.  We  speak  incorrectly  when  we  say  that  the 
hairs  are  planted  obliquely  ; their  insertion  in  the  bulb  is 
perpendicular;  it  is  in  their  passage  through  the  chorion 
that  they  change  direction. 

Besides,  these  foramina  are  not  vessels,  but  mere  com- 
munications from  the  interior  to  the  exterior  through 
which  pass  the  hairs,  the  exhalants,  the  absorbents,  the 
blood-vessels  and  the  nerves  which  go  to  the  surface  of 
the  dermis ; thus  the  subjacent  spaces  are  only  cells  in 
which  are  contained  the  vessels  of  the  glands  and  of  the 
cellular  texture.  The  dermoid  texture  should  then  be 
considered  as  a real  net-v/ork,  as  a kind  of  cellular  tex- 


DERMOID  SYSTEM, 


263 


ture,  the  cells  of  which  very  evident  within,  become  less 
so  on  the  exterior  surface,  with  which  all  communicate 
to  transmit  to  it  different  organs.  The  chorion  is  then 
the  outline,  the  frame,  if  I may  so  say,  of  the  cutaneous 
organ.  It  serves  to  lodge  in  its  spaces,  all  the  other 
parts  which  enter  into  the  structure  of  this  organ,  and 
contributes  to  give  them  the  form  they  are  to  have,  but 
is  wholly  foreign  to  them. 

Vv  hat  is  the  nature  of  this  texture,  which  enters  espe- 
cially into  the  composition  of  the  cutaneous  chorion  ? 
I know  not;  but  I think  it  has  much  analogy  with  the 
texture  of  the  fibrous  system  ; the  following  considera- 
tions support  this  analogy.  1st.  On  the  heel,  where  the 
dermoid  texture  has  the  fibrous  form  of  the  irregular  liga- 
ments, it  would  be  almost  impossible  to  distinguish  it  from 
it,  so  uniform  is  the  external  appearance ; it  has  the  same 
resistance  and  density ; the  same  sensation  is  experienced 
when  it  is  cut  with  the  bistoury.  2d.  The  dermoid  tex- 
ture becomes  yellow  and  transparent  like  the  fibrous  by 
stev/ing.  3d,  It  melts  gradually  like  it  into  gelatine, 
4th.  Like  it,  except  the  tendons  however,  it  strongly 
resists  maceration.  5th.  Sometimes  these  two  textures 
are  identified  ; for  example,  the  annular  ligaments  of  the 
wrist  evidently  send  elongations  to  the  neighbouring  der- 
moid texture.  6th,  This  texture  can  serve,  like  the 
fibrous,  for  the  insei'tion  of  muscles  ; we  see  it  in  the  face, 
where  many  of  the  fibres  of  the  orbicularis  of  the  lips 
and  the  eyelids,  and  almost  all  those  of  the  eyebrows, 
find  real  tendons  in  the  fibres  of  the  dermoid  texture. 
There  is  the  same  arrangement  in  the  cutaneous  palmar 
muscles. 

All  these  considerations  evidently  establish  many  rela- 
tions between  the  dermoid  and  fibrous  textures.  Yet  they 
are  far  from  being  the  same.  To  be  convinced  of  this  it 
is  suf&cient  to  observe  how  much  their  mode  of  sensibility 
differs,  and  how  different  also  are  their  diseases  ; it  seems 


264 


DERMOID  SYSTEM. 


at  first  as  if  there  was  no  analogy  between  them  in  this 
double  relation.  Yet  the  line  of  demarcation  is  by  no 
means  as  great  as  it  appears  to  be.  In  fact  the  acute  sen- 
sibility of  the  skin  is  not  seated  precisely  in  this  white 
texture,  which  is  interwoven  so  as  to  leave  between  its 
meshes  the  spaces  of  which  we  have  spoken,  and  which 
Ave  see  especially  on  the  surface  adhering  to  this  organ. 
The  experiment  mentioned  in  the  article  on  the  mucous 
system,  and  in  which  I irritated  the  cutaneous  organ  from 
Avithin  outwards,  evidently  proves  it.  It  is  the  surface 
on  which  the  papillae  are  found  that  especially  exhibits 
this  vital  property. 

On  the  other  hand  morbid  anatomy  proves  that  the  in- 
ternal surface  of  the  dermis,  in  which  are  especially  found 
the  texture  and  the  spaces  of  which  we  have  spoken,  is 
entirely  free  from  most  cutaneous  eruptions.  This  is  no 
doubt  true  as  it  respects  the  small  pox,  the  itch  and  many 
species  of  herpes  ; I have  satisfied  myself  of  it  as  to  the 
A'accine  vesicles,  the  miliary  eruption,  &c.  &c.  It  is 
certain  that  in  erysipelas,  the  external  surface  only  of  the 
chorion  is  coloured  by  the  blood  which  enters  the  exha- 
iants ; thus  the  slightest  pressure,  causing  the  blood  to 
flow  back,  produces  a sudden  whiteness  which  soon  dis- 
appears by  the  return  of  the  blood  into  the  exhalants.  It 
is  this  which  forms  the  essential  difference  between  simple 
erysipelas  and  phlegmon,  in  which  not  only  the  external 
face  of  the  chorion,  but  its  Avbole  texture  and  the  sub- 
jacent cellular  one  are  inflamed.  In  measles  and  scarla- 
tina, tbe  redness  is  also  very  evidently  superficial.  These 
phenomena  accord  with  those  of  injections  ; for  if  they 
succeed  at  all  in  children,  the  skin  of  the  face  and  less 
frequently  that  of  the  other  parts,  becomes  almost  entirely 
black.  Now  this  blackness  is  much  more  evident  on  the 
external  than  the  internal  surface  of  the  skin,  no  doubt  be- 
cause more  exhalants  ai’e  found  in  the  first  than  in  the 
second,  Avhich  the  arterial  trunks  only  traverse. 


DERMOID  SYSTEM. 


265 


The  preceding  considerations  evidently  prove  that  the 
texture  of  the  internal  surface  of  the  chorion,  and  even 
that  of  its  interior,  have  a vital  activity  much  less  than 
that  of  the  external  surface ; that  this  texture  is  disconnect- 
ed with  all  the  great  phenomena  which  take  place  upon 
the  skin,  with  those  especially  which  relate  to  the  sensa- 
tions and  the  circulation  ; that  it  is  in  the  papillae  that  the 
first  are  seated  and  in  the  reticular  body  the  second  ; and 
that  it  is  almost  passive  in  nearly  all  the  periods  of  activ- 
ity of  this  double  portion  of  the  dermis.  Its  functions, 
like  those  of  the  fibrous  texture,  suppose  it  to  be  almost 
always  in  this  passive  state  ; they  are  only  to  defend  the 
body  and  to  protect  it  from  the  action  of  external  bodies. 
It  is  this  which  forms  our  real  covering ; thus  its  proper- 
ties are  well  adapted  to  this  use.  Its  resistance  is  ex- 
treme. It  requires  very  considerable  weight  to  tear  very 
narrow  strips  of  chorion,  when  it  is  suspended  from  them ; 
drawn  in  various  directions,  these  strips  are  broken  also 
with  much  difiiculty. 

Yet  this  resistance  is  much  less  than  when  tannin  is 
combined  with  the  chorion.  We  know  that  when  thus 
prepared,  this  portion  of  the  skin  affords  the  strongest 
strings  we  have  in  the  arts.  I know  but  two  textures  in 
the  animal  economy,  which  unite  to  such  an  extent  sup- 
pleness and  resistance ; these  are  this  and  the  fibrous  tex- 
ture ; and  this  is  a new  character  which  approximates 
them.  We  have  seen  that  it  requires  a very  considerable 
weight  to  break  a tendon,  a strip  of  aponeurosis,  or  a liga- 
ment taken  from  a dead  body.  The  muscular,  nervous, 
arterial,  venous,  cellular  textures,  &c.  yield  infinitely 
more  easily.  If  the  dermoid  texture  had  less  extensi- 
bility, it  might  advantageously  supply  the  place  of  the 
tendons,  the  ligaments,  &c.  in  the  structure  of  the  body. 

Since  the  chorion  is  foreign  to  almost  all  the  sensitive 
and  morbid  phenomena  of  the  skin,  let  us  inquire  then 
in  what  part  of  the  dermis  these  phenomena  are  seated. 

VOL.  III.  34 


266 


DERMOID  SYSTEM. 


These  parts  exist  very  evidently  on  the  external  surface  ; 
now  we  find  on  this  surface,  1st,  what  is  called  the  reticu- 
lar body  ; 2d,  the  papillae. 

Of  the  Reticular  Body. 

Most  authors  have  considered  the  reticular  body  as  a 
kind  of  layer  applied  to  the  external  face  of  the  skin  be- 
tween the  chorion  and  the  epidermis,  pierced  with  an  in- 
finite number  of  openings  through  which  the  papillae  pass. 
I do  not  know  how  we  can  demonstrate  this  layer,  which 
escapes  according  to  the  opinion  of  most  of  them,  when 
the  epidermis  is  detached.  In  order  to  see  it  I have  em- 
ployed a great  many  means,  but  no  one  has  succeeded. 
1st.  Such  is  the  adhesion  of  the  epidermis  to  the  skin, 
that  in  a sound  state  we  can  hardly  separate  them  without 
injuring  one  or  the  other.  Yet  with  the  greatest  precau- 
tion we  see  nothing  mucous  on  the  chorion  when  it  is  laid 
bare.  2d.  A portion  of  skin  cut  longitudinally,  especially 
from  the  foot  where  the  epidermis  is  very  thick,  allows 
us  to  see  very  distinctly  on  the  divided  edge  the  boun- 
daries of  this  and  of  the  chorion  ; now  nothing  escapes 
from  about  the  line  which  separates  them.  3d.  In  ebul- 
lition in  which  the  epidermis  has  been  removed,  nothing 
remains  upon  the  internal  surface,  nor  upon  the  chorion. 
4th.  Maceration  and  putrefaction,  the  latter  especially, 
produce  upon  the  chorion  a kind  of  glutinous  layer  the 
instant  the  epidermis  is  removed.  But  this  layer  is  en- 
tirely the  product  of  decomposition.  Nothing  similar  is 
met  with  in  the  ordinary  state. 

I believe,  from  all  these  considerations,  that  there  is 
not  a substance  deposited  by  the  vessels  upon  the  surface 
of  the  chorion,  extravasated,  stagnant  upon  this  surface, 
and  representing  there  a layer  in  the  sense  in  which 
Malpighi  understood  it.  I believe  that  we  ought  to  un- 
derstand by  the  reticular  body,  a net-work  of  extremely 
fine  vessels,  whose  trunks  already  very  delicate,  after 


DERMOID  SYSTEM. 


‘267 


having  passed  through  the  numerous  pores  with  which" 
the  chorion  is  perforated,  come  and  ramify  upon  its  sur- 
face, and  contain  different  kinds  of  fluids. 

The  existence  of  this  vascular  net-work  is  placed  be- 
yond a doubt  by  fine  injections  which  change  the  colour 
of  the  skin  entirely  externally,  without  altering  it  much 
within.  This  is,  as  I have  observed,  the  principal  seat  of 
the  numerous  eruptions  most  of  which  are  really  foreign 
to  the  cutaneous  chorion. 

We  may  then  consider  the  reticular  body  as  a general 
capillary  system,  surrounding  the  cutaneous  organ,  and 
forming  with  the  papillae  a layer  between  the  chorion  and 
the  epidermis.  This  system  contains  in  most  men,  only 
white  fluids.  In  negroes,  these  fluids  are  black.  They 
have  an  intermediate  tinge  in  the  tawny  nations.  We 
know  how  much  the  shades  vary  in  the  human  race. 
Hence  the  colouring  of  the  skin  resembles  nearly  that  of 
the  hairs,  which  evidently  depends  upon  the  substance 
existing  in  their  capillary  tubes  ; it  is  analogous  to  that  of 
the  marks  at  birth,  that  are  commonly  called  naevi  ma- 
terni,  and  in  which  we  never  see  a layer  of  fluids  extra- 
vasated  between  the  epidermis  and  the  chorion. 

Moreover,  I think  we  know  but  little  as  yet  concern- 
ing this  substance,  which  fills  a part  of  the  external  capil- 
lary system.  It  does  not  circulate  in  it,  but  appears  to 
remain  there  till  another  replaces  it.  When  we  examine 
the  skin  of  a negro,  we  see  a black  teint,  and  that  is  all. 
In  maceration  I have  observed  that  this  teint  is  sometimes 
removed  with  the  epidermis,  and  that  it  sometimes  re- 
mains adhering  to  the  chorion.  It  is  very  evidently 
foreign  to  both,  since  both  have  the  same  colour  in  whites 
as  in  blacks.  It  is  never  reproduced,  after  it  has  been 
removed  ; for  cicatrices  are  white  in  all  people. 

Is  there  in  white  people  a white  substance  which,  re- 
maining in  the  external  capillary  system,  corresponds  to 
that  of  negroes,  or  does  the  colour  of  their  skin  depend 


DERMOID  SYSTEM, 


only  upon  the  epidermis  and  chorion  ? I have  been 
tempted  to  believe  that  they  also  have  a colouring  sub- 
stance, since  the  long-continued  action  of  a powerful  sun 
evidently  blackens  them.  This  circumstance  has  even 
made  me  believe  that  whiteness  is  natural  to  all  men,  and 
that  there  was  but  one  primitive  race  which  has  degene- 
rated according  to  different  climates. 

But  in  order  to  be  convinced  of  the  diversity  of  races, 
it  is  sufficient  to  observe,  1st,  tliat  the  teint  of  the  skin  is 
but  one  of  the  characters  which  distinguish  each  race,  and 
that  many  others  are  always  united  to  it.  The  nature  and 
form  of  the  hair,  the  thickness  of  the  lips  and  the  nose, 
the  width  of  the  forehead,  the  degree  of  inclination  of 
the  facial  angle,  the  whole  appearance  of  the  face,  &c.  are 
constant  attributes  which  indicate  a general  modification 
in  the  organization,  and  not  merely  a difference  of  the 
dermoid  system.  2d.  White  people  become  tawny  in 
hot  countries ; but  they  never  acquire  the  teint  of  the 
people  of  the  country.  3d.  Removed  to  cold  countries 
in  early  age,  or  even  born  in  them,  the  blacks  always  re- 
main so  ; their  shade  hardly  changes  at  all  from  genera- 
tion to  generation.  4th.  Colour  by  no  means  follows 
temperature  exactly  ; we  see  many  varieties  in  the  shades 
of  people  who  live  under  the  same  degree  of  latitude,  &c. 

Every  thing  proves  then  that  the  colour  of  the  skin  is 
but  an  insulated  attribute  of  the  different  human  races, 
though  it  is  that  which  is  most  striking  to  our  senses,  and 
that  we  should  not  attach  to  it  a greater  importance  than 
to  many  others  which  are  drawn  from  the  stature,  which 
is  oftentimes  very  small,  as  in  the  Laplanders,  from  the 
broad  and  flat  face,  as  in  the  Chinese,  from  the  dimensions 
of  the  chest,  of  the  pelvis,  the  extremities,  &c.  It  is 
from  the  differences  of  the  whole,  and  not  from  those  of 
an  insulated  part,  that  the  lines  of  demarcation  should  be 
made  which  separate  the  races.  The  European  face  and 
forms  are  in  general  the  type  with  which  we  compare  the 


DERMOID  SYSTEM. 


269 


exterior  of  the  other  nations.  The  ugliness  or  beauty  of 
the  human  races  are,  in  our  way  of  considering  it,  mea- 
sured by  the  distance  which  separates  these  races  from 
ours.  Such  is  in  fact  the  force  of  habit  with  us,  that 
we  rarely  judge  in  an  absolute  manner,  and  that  every 
object  which  is  much  removed  from  those  to  which  we 
are  accustomed,  is  disagreeable  to  us  and  sometimes  even 
disgusting. 

Besides,  the  colouring  matter  of  the  cutaneous  reticu- 
lar body  is  more  interesting  to  the  naturalist  than  to  the 
physician.  What  should  particularly  arrest  the  attention 
of  the  latter  is  the  portion  of  the  capillary  system  exte- 
rior to  the  skin  in  which  the  fluids  circulate.  In  fact,  be- 
sides the  portion  which  is  the  seat  of  colour,  there  is  evi- 
dently another  that  the  white  fluids  constantly  pervade, 
in  which  they  are  moved  with  more  or  less  rapidity,  and 
in  which  they  continually  succeed  each  other.  It  is  from 
this  portion  that  the  exhalant  pores  arise  which  furnish 
the  sweat ; it  is  this  vascular  net-work  which  is  the  seat 
of  erysipelas  and  of  all  the  cutaneous  eruptions  that  are 
foreign  to  the  chorion. 

The  blood  does  not  penetrate  it  in  an  ordinary  state, 
but  a thousand  causes  can  at  every  instant  fill  it  with  this 
fluid.  Rub  the  skin  briskly,  and  it  reddens  in  a moment. 
If  an  irritant  is  applied  to  it,  whether'it  acts  mechanically 
like  nettles,  the  appendices  of  which  penetrate  the  epi- 
dermis, or  exerts  a chemical  action,  like  the  frictions 
with  ammonia,  or  the  action  of  fire  when  a portion  of 
skin  is  held  too  near  it,  instantly  the  sensibility  of  this 
vascular  net-work  is  raised  ; it  invites  into  it  the  blood 
which  it  formerly  repelled  ; every  part  of  a surface  red- 
dens in  proportion  to  the  irritation.  If  passion  acts  pow- 
erfully upon  the  cheeks,  immediately  a sudden  redness  is 
evident  in  them.  All  rubefacients  exhibit  moreover  a 
proof  of  the  great  tendency  which  the  sensibility  of  the 
superficial  capillary  system  of  the  dermis  has  to  place 


270 


DERMOID  SYSTEM, 


itself,  if  it  be  ever  so  little  excited,  in  relation  with  the 
blood  which  in  the  ordinary  state  is  foreign  to  it. 

Vesicatories  depend  upon  the  same  principle.  Their 
first  effect  is  to  fill  with  blood  the  cutaneous  capillary 
system,  where  they  are  applied,  to  produce  in  it  a sudden 
erysipelas,  and  then  to  occasion  a copious  serous  exhala- 
tion under  the  raised  epidermis.  They  effect  in  a few 
hours  what  most  cases  of  erysipelas  do  in  many  days';  for 
we  know  that  most  of  them  terminate  by  vesicles  which 
are  raised  above  the  skin.  In  burning,  carried  sufficiently 
far  to  be  more  than  a rubefacient,  and  yet  not  so  as  to 
produce  the  horny  hardening,  there  is  also  a sudden  in- 
crease of  exhalation  under  the  raised  epidermis.  In  gene- 
ral the  production  of  every  cutaneous  bladder  is  always 
preceded  by  an  inflammation  of  the  external  surface  of 
the  skin.  This  phenomenon  is  not  exclusively  confined 
to  this  system.  We  have  seen  the  serous,  as  soon  as  it 
is  laid  bare  and  irritated  considerably,  redden  in  a short 
time  by  the  passage  of  the  blood  into  its  exhalants  ; which 
constitutes  an  inflammation  to  which  often  succeeds  a 
copious  exhalation  of  milky  or  other  kind  of  serum. 
This  exhalation  does  not  remain  upon  the  surface,  and 
does  not  form  vesicles  there,  because  it  has  no  epidermis ; 
this  is  the  only  difference  between  these  phenomena, 
which  at  first  view  do  not  appear  to  be  the  same  in  the 
serous  and  cutaneous  systems. 

It  is  not  only  the  irritation  of  the  cutaneous  organ  which 
makes  the  blood  pass  into  the  external  capillary  system. 
Whenever  the  heart  is  powerfully  excited  and  it  accele- 
rates the  course  of  this  fluid,  it  always  tends  to  go  into 
it;  this  is  what  is  evidently  seen,  1st,  after  violent  run- 
ning ; 2d,  in  the  hot  period  of  a paroxysm  of  fever. 

Upon  this  subject  I will  make  a remark  which  appears 
to  me  to  be  very  important ; it  is  that  the  capillary  sys- 
tem of  the  face  is,  more  than  that  of  all  the  other  parts 
of  the  skin,  exposed  to  be  thus  penetrated  with  blood. 


DERMOID  SYSTEM. 


271 


1st.  This  is  evident  in  the  two  cases  of  which  I have  just 
spoken,  and  in  which  the  action  of  the  heart  is  increased. 
2d.  In  the  passions,  the  skin  remains  the  same  in  the 
other  parts,  whilst  that  of  the  face  suddenly  becomes  pale 
or  red.  3d.  We  know  that  physicians  frequently  ex- 
amine the  state  of  the  facial  capillary  system,  which  is 
almost  always  affected  by  the  state  of  the  internal  viscera, 
and  is  full  of  blood  or  empty,  according  as  it  is  sympa- 
thetically influenced.  4th.  In  various  kinds  of  asphyxia, 
in  those  especially  produced  by  submersion,  by  the  vapour 
of  charcoal,  by  strangulation,  &c.  the  face  is  uniformly  of 
a violet  colour  from  the  passage  of  the  black  blood  into 
its  external  capillary  system,  into  which  it  is  brought  by 
the  arteries.  Oftentimes  the  neck  and  the  upper  part  of 
the  chest  are  also  livid  ; but  there  is  never  a discolora- 
tion of  the  inferior  parts.  5th.  In  many  diseases,  in  w’hich 
death  takes  place  by  a kind  of  asphyxia,  because  the  lungs 
are  the  first  interrupted,  the  dead  bodies  have  a violet- 
coloured  and  swollen  face  ; this  may  be  easily  observed 
by  all  who  frequent  dissecting  rooms.  There  are  a hun- 
dred subjects  in  which  the  head  has  this  lividity,  to  one 
in  which  it  is  observed  in  the  inferior  parts.  6th.  Most 
cases  of  apoplexy  produce  the  same  lividity  of  the  face. 

To  what  is  this  extreme  susceptibility  of  the  facial 
capillary  system  to  admit  the  blood  owing  ? Three  things, 
I think,  principally  contribute  to  it.  1st.  The  course  is 
already  opened  to  this  fluid,  since  the  redness  of  the 
cheeks  necessarily  supposes  its  presence  in  them,  it  only 
increases  in  quantity ; whereas  when  another  part  of  the 
dermoid  surface  becomes  red,  all  the  blood  which  enters 
it  is  almost  accidendal.  2d.  The  anatomical  arrange- 
ment of  the  capillary  system  is  more  favourable  to  this 
passage  there  than  elsewhere  ; for  it  appears  that  the  com- 
munications of  this  system  with  the  arteries  of  the  chorion 
are  more  free.  What  proves  this  is,  that  in  injections 
the  face  is  coloured  with  great  ease.  There  is  undoubt- 


272 


DERMOID  SYSTEM. 


edly  no  anatomist  who  has  not  been  struck  with  this  phe- 
nomenon, especially  in  children,  in  whom  if  the  coarse 
injections  of  our  dissecting  rooms  succeed  at  all,  the  face 
becomes  wholly  black,  whilst  the  fluid  penetrates  but 
very  little  into  the  other  parts  of  the  cutaneous  system. 
3d.  It  appears  that  there  is  a greater  sensibility  in  the 
face ; in  fact  the  same  irritant  brings  blood  there,  which 
does  not  make  it  flow  to  any  other  place.  For  example, 
a blow  equal  to  a box  on  the  ear  does  not  redden  the  skin 
of  the  arm,  whilst  it  suddenly  inflames  the  cheeks. 

The  blood  disappears  from  the  facial  capillary  system 
as  it  enters  it ; in  an  instant  the  passions  will  successively 
produce  there  the  bright  red  of  a paroxysm  of  fever,  the 
whiteness  of  syncope  and  all  the  intermediate  shades.  It  is 
even  the  extreme  ease  with  which  this  fluid  penetrates  this 
system,  that  renders  the  face  well  adapted  to  serve  as  a 
kind  of  picture,  which  the  passions  paint  by  turns  with  a 
thousand  shades,  that  are  eflfaced,  altered,  modified  and 
return  again  according  to  the  state  of  the  mind. 

I would  observe  upon  this  subject  that  the  passions 
have  in  the  face  three  means  of  expression  ; 1st,  the  capil- 
lary system,  a means  wholly  involuntary,  and  which  often 
betrays  what  we  wish  to  conceal ; 2d,  the  muscular  mo- 
tion, which,  by  contracting  or  expanding  the  features, 
expresses  the  melancholy  or  gay  emotions,  and  to  which 
belongs  as  effects,  the  various  wrinkles  of  which  we  have 
spoken  ; 3d,  the  state  of  the  eye,  an  organ,  which,  as 
Buffon  has  remarked,  not  only  receives  the  sensations, 
but  also  expresses  the  passions.  The  two  last  moans  are 
to  a certain  extent  voluntary  ; we  can  at  least  disguise 
them';  whereas  we  cannot  deceive  by  the  first.  The 
actor  imitates  anger,  joy,  &c.  because  we  can  give  these 
passions  by  contracting  the  eye-brows,  by  dilating  the 
face  in  laughing,  &c.  But  it  is  the  rouge  of  the  actress 
that  imitates  modest  chastity ; it  is  by  removing  this 
rouge  that  she  imitates  the  paleness  of  fear,  horror,  &c. 


DERMOID  SYSTEM. 


273 


I will  add  another  essential  observation  in  respect  to 
the  facial  capillary  system  ; it  is  that  it  appears  that  its 
tendency  to  receive  blood,  disposes  it  to  become  the  more 
frequent  seat  of  many  affections.  We  know,  1st,  that 
erysipelas  is  much  more  frequent  in  this  than  in  other 
parts  ; 2d,  that  the  variolous  pustules  are  remarkably  con- 
spicuous here ; 3d,  that  many  eruptions  are  more  abun- 
dant here  than  elsewhere. 

From  all  that  we  have  just  said,  it  is  evident  that  it  is 
necessary  to  distinguish  two  portions  in  the  capillary  sys- 
tem exterior  to  the  chorion.  1st.  One  is  constantly  filled 
with  the  colouring  substance  of  the  skin,  a substance  which 
appears  to  be  stagnant  like  that  of  the  hair  of  the  head, 
and  that  of  the  hair  of  the  body,  which  is  subjected  only 
to  the  slow  and  insensible  motion  of  composition  and 
decomposition  and  which  never  exhibits  that  sudden 
increase  or  diminution  of  which  we  have  just  spoken. 
2d.  The  second  is  constantly  pervaded  by  many  fluids 
which  continually  succeed  each  other  there,  and  which 
constantly  escape  by  transpiration,  and  which  are  replaced 
by  the  blood,  that  insinuates  itself  into  this  portion  of  the 
capillar)'  system.  These  two  portions  are  entirely  inde- 
pendent, and  have  probably  no  kind  of  communication. 

It  appears  that  at  the  instant  of  death  there  remains  a 
certain  quantity  of  the  white  fluids  in  the  second  portion 
of  the  exterior  capillary  system  •,  the  following  experiment, 
which  I have  frequently  made,  proves  it ; by  plunging  a 
portion  of  skin  into  boiling  water,  and  leaving  it  there  an 
instant,  the  epidermis  is  raised  up,  not  as  a whole  as  in  a 
blister,  but  in  an  infinite  number  of  small  vesicles  which  are 
formed  suddenly  on  its  surface,  and  which  contain  a serous 
fluid,  that  escapes  as  soon  as  we  open  these  vesicles. 

Papillae. 

We  call  by  this  name  those  small  eminences  that  arise 
from  the  external  surface  of  the  chorion,  and  which, 
VOL.  III.  3 5 


274 


DERMOID  SYSTEM. 


piercing  the  capillary  net-work  of  which  we  have  just 
spoken,  become  by  their  extremities  contiguous  to  the 
epidermis.  These  eminences  are  very  evident  in  the 
palm  of  the  hand  and  the  sole  of  the  foot,  where  they 
are  regularly  arranged,  in  the  form  of  small  curved  striae 
in  different  directions.  We  see  them  through  the  epider- 
mis, notwithstanding  its  thickness  in  these  places.  But 
they  are  seen  especially  when  this  has  been  in  any  way 
removed,  as  by  maceration,  ebullition,  &c.  If  we  cut 
longitudinally  a portion  of  the  chorion  of  the  foot,  with 
its  epidermis  adhering  to  it,  we  see  between  them  along 
the  divided  edge,  a line  in  the  form  of  a curved  thread, 
which  arises  from  these  small  eminences  placed  at  the 
side  of  each  other. 

In  some  other  parts  of  the  skin,  we  distinguish  the  pa- 
pillae in  a very  evident  manner ; but  in  a great  number,  the 
epidermis  being  removed,  we  see  only  a surface,  slightly 
uneven  from  some  small  eminences,  especially  towards 
the  orifices  through  which  the  hairs  and  the  vessels  pass, 
but  we  do  not  discover  those  regularly  arranged  emi- 
nences, the  papillae  properly  so  called. 

We  must  not  mistake  for  them  the  numerous  and  very 
evident  prominences,  which  render  the  skin  of  some  sub- 
jects extremely  rough.  These  prominences  are  formed, 
by  small  cellular,  vascular  or  nervous  bunches,  by  seba- 
ceous glands,  &c.  which  are  found  near  the  small  open- 
ings by  which  the  chorion  opens  under  the  epideniiis, 
and  usually  transmits  the  hairs.  These  bunches,  lodged 
in  the  small  oblique  canals  which  are  terminated  by  these 
openings,  raise  the  external  side  of  them  and  thus  form 
this  prominence.  The  following  very  curious  experi- 
ment proves  this  arrangement  ; when  the  skin  is  mace- 
rated for  two  or  three  months,  or  even  less,  on  the  one 
hand  these  little  bunches  in  which  there  is  almost  always 
a little  fat,  are  changed  into  that  white,  thick,  unctuous 
matter,  analogous  to  spermaceti,  into  which  fat  kept  a 


DERMOID  SYSTEM. 


215 


long  time  in  water  is  always  converted  ; and  on  the  other, 
the  foramina  enlarging,  as  we  have  seen,  and  the  skin 
changing  into  a kind  of  pulp,  we  can  easily  remove  it  all 
around  tliese  little  prominences,  and  see  that  they  are  con- 
tinued vvith  the  fat  which  fills  the  meshes  of  the  subjacent 
chorion,  and  which  is  also  changed  into  a hard  matter. 

Injections  have  evidently  proved  to  me  that  there  were 
vessels  in  these  cellular  bunches,  and  I have  been  con- 
vinced of  it  for  some  time  past  by  the  dissection  of  some 
subjects  that  died  of  scurvy,  in  whom  the  spots  com- 
menced by  very  small  ecchymoses,  similar  as  it  were  to 
flea-bites,  and  which  occupied  these  little  eminences.  The 
petechias  of  adynamic  fevers  have  a different  appearance ; 
but  they  belong  also  to  an  extravasation  of  blood  in  the 
cellular  texture,  occupying  the  small  pores  which  open  on 
the  exterior  of  the  chorion  to  transmit  the  vessels,  the 
hairs,  &c.  The  more  prominent  these  eminences  are,  of 
which  we  have  spoken,  the  more  uneven  is  the  skin.  In 
general  they  are  more  frequent  on  the  extremities  and  on 
the  back,  than  on  the  anterior  part  of  the  trunk.  In  the 
extremities  there  are  more  of  them  in  the  direction  of  ex- 
tension, than  in  that  of  flexion. 

We  attach  the  idea  of  a beautiful  skin,  to  that  in  which 
these  small  tubercles  are  not  found,  and  in  which  the 
chorion  is  united  at  its  external  surface.  Women  have 
commonly  this  last  arrangement  more  evident  than  men. 
The  epidermis  which  covers  these  eminences  very  often 
scales  ofl  at  that  place,  especially  from  strong  friction, 
which  contributes  still  more  to  render  the  skin  uneven, 
rough  and  harsh  to  the  touch  where  they  exist,  which 
might  induce  a belief  that  they  are  formed  by  it,  though 
it  is  always  only  accessory  to  them.  Where  it  is  very 
thick,  as  in  the  palm  of  the  hand  and  the  sole  of  the  foot, 
it  cannot  be  raised,  and  these  small  cutaneous  tubercles 
are  never  seen.  In  the  face  where  many  vessels  pass  from 
within  outwards,  by  the  little  pores  of  wnich  we  have 


DERMOID  SYSTEM. 


%l(j 

spoken,  we  meet  with  hardly  any  more  of  them.  The 
papillae  scattered  among  these  eminences,  are  in  general 
very  slightly  apparent  in  the  places  where  they  exist. 

All  anatomists  attribute  to  these  last  a nervous  struc- 
ture; they  regard  them  as  the  termination  of  all  the 
nerves  that  go  to  the  skin,  and  which,  according  to  them, 
are  expanded  to  form  these,  after  having  first  left  their 
external  covering.  Some  even  say  that  they  have  traced 
filaments  even  into  the  papillae ; I confess  that  I have 
never  been  able  to  do  it.  In  the  ordinary  state,  the  den- 
sity of  the  chorion  and^the  extreme  delicacy  of  the  fila- 
ments, are  evidently  an  obstacle  to  it.  In  the  state  of 
long  continued  maceration,  in  which  the  chorion  becomes 
pulpy  and  in  which  we  might  consequently  trace  these 
filaments,  were  it  ever  possible,  it  cannot  be  done.  I do 
not  however  deny  the  texture  attributed  to  the  papillae. 
The  acute  sensibility  of  the  skin  seems  even  to  suppose 
it  ; but  it  is  only  analogy  and  not  demonstration,  which 
establishes  this  anatomical  fact;  indeed  all  the  other 
senses,  whose  organs  are  so  sensible,  have  the  portion  of 
them  which  receives  the  impression  of  bodies  continuous 
with  a nerve. 

Action  of  different  bodies  upon  the  Dermoid  Texture. 

In  most  of  the  other  textures,  we  have  only  considered 
this  action  in  the  dead  body,  because  during  life,  these 
textures  always  removed  from  external  bodies,  cannot  be 
influenced  by  them.  Here  we  can  regard  it  in  a double 
relation,  since  the  skin  is  incessantly  in  contact  with  al- 
most all  the  bodies  of  nature. 

Action  of  Light. 

Light  evidently  acts  upon  the  dermis.  Removed  from 
its  influence,  men  are  blanched,  if  we  may  so  say,  like 


DERMOID  SYSTEM. 


277 


plants.  Compare  the  inhabitant  of  a city,  who  is  never 
exposed  to  the  influence  of  the  sun,  with  the  peasant  who 
constantly  is,  and  you  will  see  the  difierence.  It  appears 
that  it  is  the  light  and  not  the  heat  which  produces  the 
effect  of  which  I have  already  spoken ; for  individuals 
who  live  in  a warm  temperature,  but  removed  from  the 
solar  light,  become  white  like  those  of  cold  countries. 
Thus  we  know  that  some  men  who  keep  their  chambers 
always  very  hot,  are  whiter  than  others  who,  living  in  a 
less  hot  atmosphere,  are  constantly  exposed  to  the  sun. 
We  might  remain  forever  in  a bath  of  a temperature 
equal  to  the  warmest  seasons,  and  the  skin  would  not 
blacken.  Apartments  for  study  which  are  warmed  with 
stoves,  and  in  which  men  remain  as  long  as  the  labourer 
at  his  plough,  are  as  warm  as  the  atmosphere  of  summer, 
and  yet  the  skin  of  those  who  occupy  them  never  be- 
comes darker.  Besides  an  irresistible  proof  is  that  the 
clothing  which  does  not  prevent  the  action  of  caloric  upon 
the  skin,  and  which  offers  a barrier  to  the  rays  of  light 
only,  prevents  the  cutaneous  colouring  that  takes  place 
upon  the  parts  which  the  light  immediately  strikes,  as 
upon  the  hands,  the  face,  &c. 

I do  not  speak  of  the  solar  influence  upon  the  vital 
forces  of  the  skin,  as  in  cases  in  which  sun-strokes  pro- 
duce erysipelas,  or  as  when  light  is  employed  medici- 
nally to  recall  the  life  of  a part ; but  it  is  only  in  rela- 
tion to  the  dermoid  texture  that  I consider  its  action. 

Action  of  Caloric. 

The  action  of  caloric  upon  the  skin  exhibits  very  difl'er- 
ent  phenomena,  according  to  the  degree  of  it  that  it  is 
applied. 

1st.  A warm  atmosphere  expands  the  dermoid  texture 
increases  its  action,  and  makes  most  of  the  fluids  which 
form  the  residue  of  nutrition  and  digestion,  pass  off  by 
the  exhalants. 


27S 


DERMOID  SYSTEM. 


2d.  When  contracted  by  cold,  this  texture  refuses  to 
admit  those  fluids,  width  then  go  off  principally  by  the 
urine. 

3d.  The  insensible  chang’c  from  one  to  the  other  of 
these  two  states,  does  not  disturb  the  functions.  When 
this  change  is  sudden,  there  are  almost  always  alter- 
ations in  different  organs,  because  the  fluids  destined  to 
pass  out,  cannot  vary  their  direction  as  rapidly  towards 
this  or  that  organ,  as  the  cutaneous  excitement  produced 
by  the  sudden  changes  from  heat  to  cold. 

4th.  The  skin  resists  a temperature  much  greater  than 
that  of  the  body  ; it  opposes  an  insurmountable  barrier  to 
the  external  caloric,  which  tends  to  an  equilibrium  in  ani- 
mate as  well  as  inanimate  bodies.  Thus  whilst  these  last 
are  penetrated  with  this  fluid  in  a medium  warmer  than 
themselves,  and  soon  acquire  the  temperature  of  this  me- 
dium, living  bodies  remain  at  the  same  degree,  how  much 
greater  soever  the  surrounding  heat  may  be  to  their  own. 
The  curious  experiments  of  tlie  English  physicians  have 
placed  this  truth,  as  it  respects  man,  beyond  a doubt.  It 
is  unnecessary  to  give  the  detail  of  these  well  known  ex- 
periments, in  which  the  mercury  was  seen  to  descend  in 
the  thermometer,  when  the  bulb  was  placed  in  the  mouth 
and  in  which  the  skin  became  covered,  in  a heated  room, 
with  the  aqueous  vapours  of  the  air,  which  the  greater 
cold  of  the  body  condensed  upon  its  surface.  A slight 
attention  to  animals  with  cold  blood,  living  in  warm 
climates,  proves  the  same  thing.  I will  make  one  remark- 
able observation  upon  this  point,  it  is,  that  most  reptiles, 
whose  temperature  is  much  less  than  that  of  the  mammalia 
and  of  birds,  and  who  consequently  arc  brought  much 
nearer  than  them  to  the  temperature  of  winter,  cannot 
however  support  it.  They  become  torpid  and  sleep  in 
subterraneous  places,  the  heat  of  vv^hich  remains  nearly 
uniform  like  that  of  celhars,  and  do  not  awake  till  the 
milder  temperature  of  spring  stimulates  them. 


DERMOID  SYSTEM. 


279 


5th.  The  skin,  in  very  cold  climates,  seems  to  be  on  the 
other  hand  an  obstacle  which  prevents  the  internal  caloric 
from  suddenly  escaping  and  thus  placing  the  body  in  equi- 
librium with  the  surrounding  medium.  This  is  evident 
in  countries  near  the  pole.  Upon  this  subject  an  observa- 
tion the  reverse  of  the  preceding  can  be  made ; it  is  that 
the  cetaceous  animals  inhabit  seas  the  temperature  of 
which  is  most  unlike  their  own.  Whales  are  sought  for 
especially  in  the  latitudes  of  Greenland,  Spitzbergen,  &c. 
Why  do  fishes  with  warm  blood  delight  in  the  frozen  seas, 
whilst  the  amphibious 'unimals  with  cold  blood  prefer  the 
burning  heat  of  the  sun  ? I know  not. 

Let  us  observe  that  most  of  the  internal  organs  when 
exposed  in  solutions  of  continuity,  have  not  the  faculty 
of  preserving  as  well  as  the  skin,  a degree  of  independent 
temperature.  They  become  cold  or  hot  sooner  than  it  as 
long  as  they  remain  healthy.  The  intestine  brought  out 
of  the  abdomen  in  the  operation  for  hernia,  a muscle  laid 
bare,  &c.  &c.  exhibit  this  phenomenon ; thus  in  order  to 
give  them  this  faculty  of  having  an  independent  tempera- 
ture, nature  inflames  them,  and  they  thus  constantly  pre- 
serve their  heat,  whatever  may  be  that  of  the  surrounding 
medium.  The  mucous  surfaces  next  to  the  skin  resist  the 
surrounding  temperature  the  most,  as  is  seen  in  prolapsus 
of  the  rectum,  in  inversion  of  the  anus,  &c.  This  ditfer- 
ence  among  the  different  systems  is  probably  owing  to 
that  of  their  structure. 

6th.  When  the  action  of  caloric  is  carried  to  a very 
considerable  extent,  it  begins  to  act  upon  the  skin,  and  its 
eflfects  are  the  more  evident  in  proportion  as  it  is  the 
more  intense.  1st.  The  slightest  of  these  eflfects  is  to 
produce  an  evident  redness,  a kind  of  erysipelas  ; the 
caloric  then  acts  like  a simple  rubefacient.  2d.  'f'he 
second  is  to  redden  the  skin  and  then  to  produce  vesicles 
on  it.  3d.  In  the  third  there  is  a real  horny  hardening,  a 
crisping  of  the  fibres  of  the  chorion  which  contract,  like 


280 


DERMOID  SYSTEM. 


those  of  all  the  animal  textures  exposed  to  too  strong  a 
degree  of  heat.  4th.  In  the  fourth  and  last  effect,  the 
dermoid  texture  is  burnt,  blackened  and  reduced  to  mere 
carbon.  These  different  degrees  of  burning  arise  only 
from  different  degrees  of  caloric.  1 would  observe  that 
in  the  two  first  effects,  this  fluid  acts  upon  the  vital  forces, 
and  that  these  two  effects  cannot  consequently  take  place 
except  during  life.  The  two  last  are  exerted  only  upon 
the  texture  of  the  organ  ; thus  they  take  place  after  death 
precisely  as  before.  Cooks  often  employ  the  horny  hard- 
ness, to  give  to  the  skin  a hardness  and  brittleness  neces- 
sary in  some  kinds  of  cooking. 

7th.  Cold  carried  to  a gx’eat  degree  acts  also  upon  the 
cutaneous  organ,  and  produces  different  effects,  according 
to  its  intensity.  The  first  of  these  effects  is  very  analo- 
gous to  the  first  effect  of  a slight  degree  of  caloric.  It 
consists  of  a kind  of  local  inflammation.  The  tip  of  the 
nose,  the  ears  and  the  fingers,  the  cheeks,  &c.  become  red 
from  a slight  degree  of  cold.  I have  not  accurately  ob- 
served the  other  effects  between  this  and  the  last,  which 
consists  in  a sudden  privation  of  life.  But  there  is  this 
difference  between  the  gangrene  that  then  takes  place,  and 
that  produced  by  a high  degree  of  caloric,  that  the  black- 
ness is  sudden  in  this  last,  whereas  it  takes  place  only  as 
a consequence  in  the  other.  Observe  in  fact  that  there  is 
in  gangrene  two  things  which  physicians  do  not  suffi- 
ciently distinguish,  1st,  the  mortification  of  the  part ; 2d, 
its  putrefaction.  The  mortification  is  always  antecedent; 
it  is  produced  by  a thousand  different  causes ; sometimes 
by  the  ligature  of  an  artery,  as  in  aneurism  ; sometimes 
by  that  of  a nerve  ; often  by  violent  inflammation  ; some- 
times by  a contusion,  attrition,  a bruise,  &c.  Whenever 
a part  is  dead  in  the  midst  of  those  which  live,  whatever 
may  be  the  cause  of  its  death,  it  becomes  putrid  precisely 
like  a dead  body,  every  part  of  which  life  has  left.  Putre- 
faction takes  place  then  even  sooner,  because  on  the  one 


DERMOID  SYSTEM. 


281 


hand  the  natural  heat  of  the  body,  and  on  the  other  the 
moisture  of  the  surrounding  parts,  favour  it  remarkably. 
This  putrefaction  varies  according  to  the  state  in  which 
the  ]3art  was  at  the  instant  of  death.  If  much  blood  in- 
filtrated it,  as  when  inflammation  destroys  life,  it  quickly 
becomes  putrid,  blackens  immediately  and  allows  a fetid 
sanies  to  escape  ; this  putrefaction  is  called  moist.  If 
there  is  but  little  blood  in  the  part  at  the  instant  of  death, 
its  putrefaction  is  less  sudden  ; it  first  putrifies,  then  black- 
ens, and  allows  but  little  sanies  to  escape  ; this  is  the  dry 
gangrene.  Thus  in  a dead  body,  if  one  part  is  much 
loaded  with  blood,  as  the  head  of  those  that  have  died  of 
apoplexy,  its  putrefaction  is  much  more  rapid  and  moist 
than  that  of  the  parts  in  wh’ch  this  fluid  is  less  abundant. 
In  the  gangrene  which  succeeds  mortification  produced  by 
cold,  there  is  often  dryness  of  the  part,  because  there  was 
but  little  blood  in  it  at  death.  How  little  many  physi- 
cians know  of  the  progress  of  nature  in  the  employment 
of  antiseptics,  which  they  apply  in  the  living  economy, 
as  upon  flesh  without  life.  Antiseptics  are  applied  for 
one  of  two  purposes,  either  to  prevent  the  death  of  the 
part,  or  its  putrefaction.  1st.  If  it  is  with  the  first  inten- 
tion, antiseptics  should  be  varied.  By  untying  the  artery 
of  a limb  of  an  animal  that  has  been  tied,  you  will  per- 
form an  antiseptic  operation.  Bleeding  and  emollient  ap- 
plications which  lessen  the  violence  of  inflammation  in  a 
phlegmon,  are  antiseptics.  A tonic  as  wine  and  all  stimu- 
lants which  excite  the  vital  forces  in  a part  in  which  they 
are  languid  after  a bruise,  are  antiseptics.  This  word  is 
then  extremely  improper  when  it  is  applied  to  medicines 
designed  to  prevent  the  mortification  of  the  parts.  Anti- 
septics are  employed  to  prevent  a dead  part  in  the  midst 
of  living  ones  becoming  putrid  ; some  effect  is  obtained  ; 
thus  by  sprinkling  cinchona,  mui’iate  of  soda,  or  any  neu- 
tral salt,  by  moistening  a limb,  a portion  of  skin,  the  ex- 
VOL.  III.  36 


283 


DERMOID  SYSTEM. 


tremity  of  the  nose,  &c.  which  is  dead  from  any  cause, 
the  putrefaction  will  be  arrested,  as  in  a dead  body  upon 
which  the  same  means  are  employed.  But  what  will  be 
the  result  of  it?  a little  less  fetor  in  the  surrounding  parts 
and  less  danger  of  their  receiving  the  influence  of  the 
emanations  of  the  dead  part ; but  it  is  always  necessary 
that  this  should  come  off;  antiseptics  will  never  bring  it 
to  life.  Hence  it  is  evident  that  these  means  should  be 
considered  in  two  points  of  view  entirely  different.  The 
first  prevent  mortification,  and  vary  remarkably  though 
they  are  designed  to  eflfect  the  same  object ; thus  our 
means  of  curing  retention  of  urine  are  very  variable,  often- 
times opposite,  according  to  the  cause  which  tends  to  pro- 
duce this  retention.  The  others  prevent  putrefaction, 
without  restoring  the  parts  to  life  ; now  these  are  uni- 
formly the  same,  whatever  may  have  been  the  cause  of 
the  local  death. 

Action  of  the  Air. 

The  air  acts  incessantly  upon  the  cutaneous  organ.  In 
the  ordinary  state,  it  constantly  removes  from  its  surface 
the  sweat  that  is  exhaled  from  it.  Fourcroy,  who  has 
paid  particular  attention  to  the  solution  of  the  transpired 
fluid  by  the  surrounding  air,  appears  to  me  to  have  allow- 
ed too  much  influence  to  this  solution  upon  transpiration. 
In  fact  there  are  two  very  distinct  things  in  this  function  ; 
1st,  the  action  of  the  exhalants  which  throw  out  the  fluid  ; 
2d,  the  action  of  the  air  which  dissolves  and  evaporates 
it.  Now  the  first  of  these  is  wholly  independent  of  the 
other.  Whether  the  fluid  is  dissolved  or  not,  more  is  still 
furnished  by  the  exhalants.  If  the  solution  does  not 
take  place,  the  fluid  accumulates  upon  the  skin,  which  re- 
mains moist ; but  this  moisture  does  not  obstruct  the  ex- 
halant  pores  and  prevent  new  moisture  from  being  added 
to  it.  A comparison  will  render  this  very  evident.  In 
the  natural  state,  the  serous  fluids  are  constantly  exhaled 


DERMOID  SYSTEM. 


283 


and  absorbed  ; the  absorbents  perform  for  them  the  func- 
tions of  the  air  which  dissolves  the  sweat ; now,  though 
these  vessels  cease  to  act,  as  in  dropsies,  the  exhalants 
continue  their  action  ; there  arises  only  a serous  collec- 
tion, which,  though  applied  to  the  orifices  of  the  exha- 
lants, does  not  prevent  them  from  pouring  out  more 
serum.  The  bladder  in  vain  contains  urine  which  presses 
upon  the  opening  of  the  ureters,  these  ducts  do  not  pour 
less  into  it.  Though  the  mucous  juices  become  stagnant 
on  their  respective  surfaces,  new  juices  are  however  pour- 
ed upon  these  surfaces.  So  though  the  skin  remains  moist 
from  the  want  of  solution  of  the  transpiration,  more 
transpiration  is  nevertheless  exhaled.  Solution  is  a physi- 
cal phenomenon  wholly  foreign  to  the  vital  phenomenon 
of  exhalation.  We  transpire  in  a bath  as  well  as  in  the 
air ; only  the  fluid  which  arises  from  it  is  mixed  with  the 
water,  instead  of  being  reduced  to  vapour. 

The  moisture  of  the  skin  is  owing  to  two  causes  wholly 
foreign  to  each  other;  1st,  to  the  increase  of  the  fluid 
furnished  by  the  cutaneous  exhalants  ; now  the  action  of 
these  exhalants  may  be  increased  from  three  causes. 
First,  every  thing  which  accelerates  the  motion  of  the 
heart,  as  running,  the  paroxysm  of  acute  fevers,  &c. 
drives  to  the  skin,  as  it  is  commonly  expressed.  In  the 
second  place,  every  thing  which  tends  to  relax  and  ex- 
pand the  cutaneous  organ  by  a direct  action  exerted  upon 
it  by  the  surrounding  bodies,  increases  also  the  action  of 
these  exhalants,  as  in  the  great  heat  of  summer,  as  in  a 
bath  and  after  coming  out,  as  in  a heated  room,  &c.  In  the 
third  place,  the  action  of  the  skin  is  in  many  cases,  sym- 
pathetically increased.  Here  may  be  classed  the  sweats 
of  phthisis  of  which  the  lungs  are  the  source  ; those  of 
fear,  which  depend  upon  a sudden  aSection  of  an  epigas- 
tric organ  ; those  of  many  acute  diseases,  &c.  Now  in 
all  these  cases,  however  active  the  solution  by  the  air  may 
be,  the  skin  will  be  constantly  moist,  because  there  is 


284 


DERMOID  SYSTEM. 


thrown  out  upon  it  more  fluid  than  the  air  can  dissolve. 
Thus  in  catarrhs  of  the  lungs,  in  which  more  mucous 
juices  are  thrown  into  the  bronchia  than  the  air  can  re- 
move, it  is  absolutely  necessary  that  there  should  be  cough 
and  expectoration  to  carry  off  the  remainder. 

2d.  There  are  cases  in  which  the  moisture  of  the  skin 
arises  from  the  solution  not  being  sufficient.  This  is 
what  takes  place  in  the  moisture  of  the  bed  in  which  the 
air  is  not  changed,  in  damp  weather,  &c.  There  is  not 
then  more  fluid  exhaled ; but  the  ordinary  fluid  becomes 
evident,  because  it  is  not  dissolved.  It  is  under  this  point 
of  view  that  we  must  consider  the  action  of  the  air  upon 
the  cutaneous  organ  which  transpires.  It  carries  off 
nothing  in  this  organ ; it  has  no  real  action  upon  it ; it 
takes  only  what  its  vessels  throw  off.  Solution  is  merely 
accessory,  it  is  always  subsequent  to  exhalation,  and  has 
no  relation  with  it.  In  the  same  daj’",  in  which  the 
temperature  has  remained  the  same,  the  skin  is  often  dry, 
moist,  humid  and  even  wet  with  sweat.  If  the  air  acts 
upon  transpiration,  it  is  by  contracting  or  relaxing  the  ex- 
halants,  and  not  by  dissolving  what  they  throw  out.  If 
the  skin  formed  a sac  without  an  opening,  like  the  serous 
surfaces,  transpiration  would  go  on  though  it  was  remov- 
ed from  the  contact  of  the  air,  the  same  as  if  in  contact 
with  it.  Why  in  fact  should  not  that  take  place  there, 
which  does  upon  these  surfaces  ? 

If  we  consider  the  action  of  the  air  upon  the  skin  of 
the  dead  body,  we  see  that  it  produces  two  different 
effects,  according  to  the  state  of  the  body.  If  the  air 
penetrates  the  skin  on  all  sides,  it  dries  it,  and  it  then 
acquires  a sort  of  transparency,  like  the  fibrous  organs, 
unless  a large  quantity  of  blood  had  been  accumulated  in 
it  at  the  moment  of  death,  in  which  case  it  becomes  black 
or  of  a deep  brown.  Thus  dried,  1st,  it  is  firm  and  re- 
sisting, but  can  be  bent  in  various  directions  without 
breaking,  as  is  the  case  with  many  textures  thus  dried,  as 


DERMOID  SYSTEM. 


285 


the  cartilaginous,  the  muscular,  &c.  &c,  2d.  It  is  much 

less  easily  altered  than  most  of  the  other  textures  in  a 
dried  state.  3d.  It  absorbs  moisture  less  easily  than 
them,  though  however  when  immersed  for  a long  time  in 
water,  it  finally  resumes  nearly  its  original  colour  and 
loses  its  transparency.  4th.  It  does  not  exhale  a very 
disagreeable  odour,  like  many  of  the  other  textures. 
Hence  why  the  skins  of  animals,  merely  dried,  are  used 
in  many  of  the  arts ; why  some  barbarous  people  make 
use  of  them  for  clothing,  &c.  The  aponeuroses,  and  the 
mucous,  serous  and  fibrous  membranes  could  not  be  thus 
employed.  It  is  to  this  also  that  must  be  attributed  the 
little  alteration  that  takes  place  in  the  exterior  of  mum- 
mies, which  would  never  last  for  ages,  if  clothed  with  a 
fleshy  or  serous  covering. 

When  the  skin  is  left  upon  the  dead  body,  or  exposed 
to  a moist  air,  it  becomes  putrid  instead  of  drying.  Then 
it  takes  at  first  a dull  colour,  then  a green  and  finally  a 
black  one.  It  exhales  a very  great  fetor,  swells  and  thick- 
ens, because  the  gases  which  are  disengaged  there  fill  the 
cellular  texture  in  its  little  spaces.  A mucous  covering 
is  spread  upon  its  external  surface,  which  is  deprived  of 
its  epidermis.  Nothing  similar  to  this  covering  is  seen 
on  the  internal  surface.  Finally,  when  all  the  fluids  it 
contains  are  evaporated,  there  remains  a black  residuum, 
very  different  from  that  which  is  left  after  combustion. 

Action  of  Water. 

This  action  during  life,  is  relative  either  to  the  sub- 
stances that  are  deposited  on  the  surface  of  the  skin,  or 
to  the  cutaneous  texture  itself. 

The  sweat  deposits  incessantly  upon  the  epidermis 
many  substances,  the  principal  of  which  are  taken  away 
by  the  air,  but  many  being  slightly  soluble  in  it,  as  the 
salts  for  example,  remain  on  its  surface,  and  adhere  to  it 


286 


DERMOID  SYSTEM. 


when  not  i-emoved  by  friction.  Mixed  with  the  unctu- 
ous fluid  which  oozes  out  upon  this  surface,  and  with  the 
different  foreign  particles  that  the  air  deposits  there  as 
everywhere  else,  these  substances  form  upon  the  skin  a 
deposit  which  cannot,  like  the  transpiration,  be  carried  off 
by  solution.  Now  water  removes  all  this  deposit ; hence 
why  the  use  of  baths  is  truly  natural.  All  quadrupeds 
bathe  themselves.  All  birds  frequently  plunge  into  the 
water  ; I do  not  speak  of  those  for  whom  this  fluid  is  as 
it  were  the  element.  It  is  a law  imposed  upon  all  species 
of  animals  whose  skin  throws  out  a considerable  quantity 
of  fluid.  All  the  human  races  hitherto  observed  fre- 
quenty  plunge  into  brooks,  rivers,  or  lakes,  along  which 
they  take  up  their  abode.  The  countries  that  are  well 
watered  are  those  which  animals  prefer.  They  avoid 
those  where  this  fluid  is  wanting,  or  in  which  it  is  only 
sufficient  for  their  drink.  We  oppose  nature  in  every 
thing  in  society.  In  our  own,  numerous  classes  hardly 
ever  use  a bath ; thus  you  must  seek  especially  in  these 
classes  for  cutaneous  diseases.  We  have  seen  that  the 
mucous  juices,  remaining  too  long  upon  their  surfaces, 
irritate  and  stimulate  them  and  cause  there  various  affec- 
tions. Is  it  astonishing  that  the  residuum  of  the  cuta- 
neous exhalation  which  the  air  does  not  remove,  should 
occasion  various  alterations  upon  the  skin?  In  summer, 
baths  are  more  necessary,  because  as  many  excretions  are 
taking  place  by  the  skin,  more  substances  are  deposited 
there.  In  winter,  in  which  every  thing  passes  off  by 
the  urine,  the  cutaneous  surface  becomes  less  dirty,  and 
has  less  need  of  being  cleansed.  After  severe  diseases, 
in  which  there  has  been  copious  cutaneous  evacuations, 
one  or  two  baths  terminate  the  treatment  advantageously. 
Let  us  consider  water  then  as  acting  as  accessory  to  the 
air  upon  the  skin,  as  removing  from  its  surface  sub- 
stances which  the  first  cannot  dissolve,  substances,  which 
varying  remarkably  like  those  that  compose  the  urine, 


DERMOID  SYSTEM. 


281 


have  presented  the  transpiratory  fluids  to  chemists,  some- 
times as  alkaline,  sometimes  as  acid,  oftentimes  as  con- 
taining salts,  sometimes  charged  with  odoriferous  sub- 
stances, &c.  Water  is  the  general  vehicle  ; when  it  is 
evaporated,  it  leaves  the  substances  that  are  not  volati- 
lized like  it.  It  is  on  this  account  that  dry  frictions  are 
also  advantageous  ; they  clean  the  exterior  of  the  body. 

As  to  the  action  of  the  bath  upon  the  cutaneous  tex- 
ture, we  know  but  little  of  it  during  life.  They  say  in 
medicine  that  it  softens,  relaxes  and  unbends  this  texture ; 
this  is  vague  language  to  which  no  precise  meaning  is 
attached,  and  which  is  no  doubt  borrowed  from  the  re- 
laxation which  the  skin  of  dead  bodies  undergoes,  or  even 
tanned  leather,  when  exposed  to  water.  A bath  acts 
upon  the  vital  forces  of  the  skin,  raises  or  diminishes 
them,  as  I shall  say  ; but  it  leaves  its  texture  in  the  same 
state';  it  is  only  that  of  the  epidermis  which  it  alters,  as 
we  shall  see. 

Macerated  in  water  of  a moderate  degree  of  tempera- 
ture, in  that  of  cellars  for  example  which  does  not  vary, 
the  human  skin  softens,  swells  but  little,  becomes  evi- 
dently whiter,  and  remains  for  a long  time  without  ex- 
periencing any  other  alteration  than  that  of  a putrefaction 
infinitely  less  than  that  of  the  muscular’,  glandular,  mu- 
cous textures,  &c.  subjected  to  the  same  experiment. 
This  putrefaction,  which  removes  the  epidermis,  appears 
to  be  much  greater  on  the  side  nearest  to  this  membrane ; 
at  the  end  of  two  or  three  months  the  skin  loses  but  little 
&f  its  consistence.  It  does  not  become  pulpy  as  the  ten- 
dons and  muscles  in  this  length  of  time  when  macerated  ; 
it  does  not  become  a fetid  pulp  till  the  end  of  three  or  four 
months.  I have  preserved  some  of  it  for  eight  months, 
which  has  still  its  primitive  form,  but  which  feels  liquid 
under  the  fingers  when  pressed  a little.  In  the  half  putrid 
state,  the  skin  still  preserves  the  faculty  of  crisping 
from  the  action  of  caloric  ; it  moves  about  when  placed 


288 


DERMOID  SYSTEM, 


on  burning  coals,  or  when  plunged  into  boiling  water. 
When  once  reduced  to  a really  putrid  state  it  loses  this 
property. 

Exposed  to  ebullition,  the  dermoid  texture  \Vhen  well 
separated  from  the  cellular,  furnishes  less  scum  than  the 
muscular,  the  glandular  and  the  mucous  ; it  resembles  in 
this  respect  the  tendons,  no  doubt  because  being  almost 
wholly  gelatinous,  it  contains  but  little  albumen.  In  the 
horny  hardening  that  takes  place  a little  before  ebullition 
commences,  it  twists  and  then  always  becomes  convex  on 
the  side  of  the  epidermis,  and  concave  on  the  opposite 
side ; and  for  this  reason ; the  fibres  of  the  chorion  in 
contracting  by  the  horny  hardening,  are  pressed  against 
each  other  ; all  the  spaces  which  exist  between  them  are 
effaced  ; now,  as  these  spaces  are  very  large  in  the  second 
direction,  the  dermoid  texture  necessarily  becomes  more 
contracted  there,  whilst  in  the  first,  the  spaces  hardly 
existing  at  all,  every  thing  being  almost  solid,  the  fibres 
have  less  space  to  contract,  they  remain  longer,  and  the 
surface  continues  larger.  In  the  natural  state  the  cavity 
of  these  spaces,  being  filled  with  cellular  texture,  in- 
creases the  extent  of  the  internal  surface ; this  space  then 
disappearing,  this  surface  becomes  contracted. 

The  moment  this  kind  of  twisting  takes  place  upon  the 
skin,  it  is  covered,  as  I have  said,  with  an  infinite  number 
of  vesicles  filled  with  serum,  and  which  are  formed  by 
the  epidermis.  As  this  membrane  is  very  thick  on  the 
soles  of  the  feet  and  the  palms  of  the  hands,  it  cannot 
contribute  in  tliose  places  to  their  formation,  and  we  see 
nothing  there  similar  to  them.  Yet  by  removing  it  from 
feet  that  have  been  boiled,  I have  observed  that  it  con- 
tained between  its  layers  many  small  vesicles,  which  were 
scarcely  visible.  I have  not  analyzed  tlie  water  of  these 
vesicles,  but  presume  it  is  analogous  to  that  of  blisters. 
Besides  a greater  or  less  quantity  of  it  is  poured  out,  and 
the  vesicles  are  consequently  larger  or  smaller,  according 


DERMOID  SYSTEM. 


289 


to  the  state  of  the  external  capillary  system  at  the  instant, 
of  death. 

By  the  horny  hardening,  the  skin  becomes  hard,  elastic, 
very  resisting,  thicker,  but  not  so  broad.  It  soon  loses 
its  serai-transparency  and  yellowish  colour,  like  the  boiled 
fibrous  organs.  Then  the  hardness  it  had  acquired  at  the 
instant  of  the  horny  hardening  is  gradually  lost  ; it  softens, 
gives  out  luuch  gelatine  in  the  water  in  which  it  is  boiled, 
does  not  lessen  in  size,  but  even  increases  in  thickness. 
Every  kind  of  fibre,  vacant  space  and  organization  is  then 
gone  ; it  is  a membranous  mass,  homogeneous  in  appear- 
ance, semi-transparent  and  gelatinous.  In  this  soft  state, 
it  does  not  lose  the  elasticity  it  had  acquired  in  the  horny 
hardening,  like  the  mucous,  serous,  cellular  textures,  &c. 
&c.  The  great  quantity  of  gelatine  it  contains  still  pre- 
sei'ves  this  property  in  it.  The  least  motion  that  is  com- 
municated to  it  produces  a general  trembling,  a sort  of 
vibration  of  all  its  parts,  exactly  analogous  to  that  of  the 
various  kinds  of  animal  jellies,  half  coagulated,  which 
vaccillate  in  the  vessel  from  the  least  jar. 

Finally,  the  ebullition  still  continuing,  the  gelatine  is 
almost  all  dissolved,  and  there  remains  only  a residuum 
like  membrane  and  which  disappears  with  great  difficulty ; 
it  requires  even  a very  long  time  for  common  boiling 
water  to  reduce  the  skin  to  this  residuum.  Such  are  the 
phenomena  of  the  ebullition  of  the  human  skin  as  I have 
carefully  observed  them.  Chemists  have  paid  great  atten- 
tion to  the  dermoid  texture  of  many  other  animals  ; they 
have  formed  difierent  ideas  of  its  nature ; they  have  ad- 
mitted that  there  are  two  substances  in  it ; one  fibrous 
and  the  other  gelatinous.  I refer  to  their  works  upon  this 
point,  particularly  to  the  labours  of  Seguin,  and  the 
work  of  Fourcroy  ; for  in  general  I do  not  relate  what 
is  detailed  by  others,  it  would  be  only  a useless  repeti- 
tion. 


VOL.  iir. 


37 


290 


DERMOID  SYSTExM. 


Action  of  the  ^cids,  the  Alkalies  and  other  Substances. 

The  sulphuric,  nitric  and  muriatic  acids  act  upon  the 
skin,  when  in  contact  with  it,  as  upon  all  the  other  animal 
substances.  I have  remarked  however  that  their  action 
is  much  slower,  especially  on  the  side  of  the  epidermis, 
though  this  membrane  may  have  been  previously  taken 
off.  The  first  of  these  acids  reduces  it  easily  to  a blackish. 
pCilp ; the  others  bring  it  to  a pulpy  state  witli  more 
difficulty,  even  when  they  are  very  little  weakened ; the 
oxy-muriatic  acid  produces  hardly  any  effect  upon  it. 

Some  authors  have  said  that  the  lapis  infernalis  pro- 
duces the  same  phenomena  on  the  dead  as  on  the  living 
body.  I wrapped  up  in  a piece  of  skin,  as  in  a rag, 
many  fragments  of  this  substance,  so  that  they  were  in 
contact  with  the  epidermis  ; at  the  end  of  a day  they  were 
reduced  to  a kind  of  pap  of  a yellowish  red,  by  the  mois- 
ture which  they  had  absorbed.  The  dermoid  texture, 
crisped  and  contracted,  had  not  been  penetrated  ; it  did 
not  appear  even  to  have  been  injured  on  the  exterior. 
In  general  the  action  of  the  alkalies  appears  to  be  wholly 
different  during  life,  and  it  varies  even  according  to  the 
different  degrees  of  vitality.  We  know  that  flaccid  and 
fungous  flesh  burns  much  less  easily  than  that  which  is 
red  and  vigorous.  It  is  the  same  with  the  acids.  Never 
during  life  do  they  produce  any  thing  analogous  to  that 
pulp  of  different  colours  according  to  the  acids  that  are 
employed,  which  is  always  after  death  the  result  of  their 
action. 

We  know  that  an  alkaline  solution,  put  in  contact  with 
the  skin,  produces  a kind  of  unctuous  and  slippery  feel, 
which  is  no  doubt  owing  to  the  combination  of  the  alkali 
with  the  oily  deposit  of  the  skin,  from  which  arises  a sort 
of  soap. 

I shall  not  speak  of  the  tendency  of  the  dermis  to  com- 
bine with  tannin,  nor  of  the  phenomena  of  this  combina- 


DERiMOID  SYSTEM. 


291 


tion ; I should  only  be  able  to  repeat  wbat  others  have 
said  upon  this  point.  I will  merely  remark  that  it  would 
be  very  important  to  try  the  effects  of  tannin  on  the  large 
sub-cutaneous  aponeuroses,  the  texture  of  which  being 
essentially  gelatinous  has  much  analogy  with  that  of  the 
dermis,  and  which  from  their  extent  and  delicacy  might 
serve  for  uses  to  which  the  dermoid  texture  when  tanned 
is  less  adapted.  We  know  that  the  tanned  skin  is  no 
longer  what  it  was  in  the  natural  state,  and  that  the  sub- 
stance with  which  it  is  then  penetrated  gives  it  an  artifi- 
cial consistence.  If  much  tannin  has  been  combined  with 
it,  it  loses  entirely  the  faculty  of  acquiring  the  horny 
hardness,  and  becomes  brittle  ; whilst  if  but  little  hf  this 
substance  is  . added  to  it,  it  preserves  in  part  its  supple- 
ness and  the  property  of  crisping  from  the  action  of 
caloric.  I would  compare  tanned  skin  to  bone  penetrated 
with  the  phosphate  of  lime,  and  that  which  is  not  tanned, 
to  the  cartilaginous  parenchyma  from  which  the  acids 
have  removed  this  phosphate. 

II.  Parts  common  to  the  Organization  of  the  Dermoid 
System.  Cellular  Texture. 

The  whole  dermis  is  penetrated  with  a large  quantity 
of  this  texture.  It  is  arranged  in  the  following  way ; 
from  the  exterior  of  the  sub-cutaneous  cellular  layer,  an 
infinite  number  of  elongations  is  detached  which  pene- 
trate the  contiguous  spaces  of  the  chorion,  enter  after- 
wai’ds  into  those  which  are  more  exterior,  and  finally  ter- 
minate in  the  numerous  pores  which  transmit  outwards 
the  vessels,  the  nerves  and  the  hairs,  which  have  pre- 
viously passed  through  this  cellular  texture.  We  can 
then  consider  the  chorion  as  a kind  of  sponge,  the  spaces 
of  which  represent  the  interstices,  and  which  the  cellular 
texture  penetrates  on  all  sides  ; so  that  if  it  was  possible 
to  separate  by.  dissection,  these  spaces  from  the  cellular 


292 


DERMOID  SYSTEM. 


textuj’e,  and  the  organs  which  are  in  it,  there  would  be  a 
kind  of  sieve  pierced  in  all  directions.  Art  cannot  arrive 
at  it  but  with  difficulty  on  account  of  the  delicacy  of  the 
parts;  but  that  which  is  not  done  b)"^  dissection,  nature 
often  effects.  In  biles  I have  observed  that  all  that  which 
fills  the  interstices  of  the  dermoid  fibres  disappears  by 
suppuration,  and  that  these  fibres,  separated  besides  by 
the  swelling  of  the  parts,  exhibit  truly  the  appearance  of 
a sieve  of  which  I have  just  spoken,  when  the  fluid  that 
moistens  them  is  removed.  The  bile  differs  in  fact  from 
many  other  cutaneous  eruptions,  in  this  that  it  attacks  the 
cellular  texture  of  the  spaces  of  the  chorion,  whilst  they 
have  their  seat,  as  I have  said,  in  the  reticular  body.  I 
do  not  know  any  acute  affection  which  attacks  the  chorion 
itself ; all  have  their  seat  either  on  its  si^rface,  or  in  the 
cellular  texture  of  its  cells.  Its  dense  and  compact  tex- 
ture seems,  like  that  of  the  aponeuroses,  not  able  to  be 
changed  until  a length  of  time.  In  elephantiasis  I have 
seen  this  texture  evidently  disorganized. 

M.  Thillaye  showed  me  portions  of  skin  taken  from  a 
cemetery,  in  wffiich  every  thing  that  filled  the  dermoid 
spaces  had  disappeared,  and  in  which  these  spaces  and  their 
dried  fibres  formed  a real  membranous  sponge  through 
which  the  light  could  everywhere  be  seen.  In  this  case 
the  reverse  of  what  is  seen  in  long  continued  macerations 
had  taken  place,  in  whicli  the  fatty  cellular  texture, 
changed  into  a solid,  white  substance,  preserves,  as  I have 
said,  the  form  of  the  spaces  which  it  filled,  whilst  the 
dermoid  fibres  reduced  to  the  pulpy  state,  are  easily  re- 
moved. In  the  first  case  it  is  the  mould  only  which  is 
left ; in  the  second  it  is  the  substance  which  is  contained 
in  it. 

In  chronic  leucophlegmasia,  the  sub-cutaneous  serum 
gradually  extends  along  the  cellular  elongations  of  the 
spaces  of  the  dermis,  separates  their  fibres,  consequently 
enlarges  these  spaces,  and  sometimes  penetrates  even  to 


DERMOID  SYSTEM. 


293 


the  epidermis,  which  it  breaks  in  different  places,  and 
through  the  crevices  of  which  it  escapes.  In  this  case, 
there  is  not  resolution  of'the  skin  into  cellular  texture, 
as  it  is  called,  but  a separation  of  the  dermoid  fibres, 
which  always  remain. 

I do  not  presume  that  the  cellular  texture  of  the  chorion 
extends  to  its  external  surface,  under  the  epidermis ; for 
when  this  has  been  removed,  fleshy  granulations  are  not 
formed,  now,  in  all  the  parts  where  the  cellular  texture  is 
found,  these  granulations  are  produced,  when  the  parts 
are  laid  bare. 

Blood  Vessels. 

The  arteries  winding  in  the  sub-cutaneous  cellular  tex- 
ture, furnish  an  infinite  number  of  small  branches  which 
are  introduced  with  the  cellular  parcels  into  the  most  in- 
ternal dermoid  spaces,  afterwards  pass  into  those  that  are 
nearer,  approximate  by  winding  and  anastomosing  a thou- 
sand times  through  the  spaces  of  the  external  surface  of 
the  chorion,  finally  go  through  the  pores  of  this  surface, 
and  give  rise  to  that  external  capillary  net-work  of  which 
we  have  spoken  in  the  article  upon  the  reticular  body, 
and  to  which  in  the  ordinary  state  but  very  little  red 
blood  comes.  In  this  course  through  the  dermoid  spaces, 
but  few  small  arteries  remain  in  the  fibres  of  the  chorion 
itself,  as  fine  injections  prove.  These  fibres  resemble  in 
this  respect  those  of  the  aponeuroses  through  which  many 
vessels  pass,  but  which  have  but  few  belonging  to  their 
own  texture. 

The  veins  follow  nearly  the  motion  of  the  arteries,  but 
in  an  inverse  direction.  After  having  passed  through 
the  dermoid  spaces  and  the  cellular  texture  which  fills 
them,  they  go  to  the  great  sub-cutaneous  trunks,  which 
run  a long  course,  form,  as  we  have  seen,  a system  wholly 
distinct  by  its  position  from  that  of  the  arteries  and  which 
xan  be  often  traced  through  the  integuments.  Not  seen, 


294 


DERMOID  SYSTEM, 


in  the  natural  state,  the  venous  ramifications  of  the  spaces 
of  the  chorion  are  considerably  dilated  in  the  subjacent 
cancerous  tumours,  and  make  the  skin  which  covers  these 
tumours  appear  to  be  marked  with  blue  lines,  which 
always  grow  larger  as  the  tumour  increases.  Whenever 
there  is  a considerable  distention  of  the  cutaneous  organ 
by  an  aneurism,  pregnancy,  dropsy,  &c.  this  dilatation  also 
takes  place,  provided  the  cause  of  the  distention  pursueSi 
a chronic  course ; for  nothing  similar  is  seen  in  acute 
afiections,  whatever  swellings  may  have  taken  place,  as 
in  those  consequent  upon  fractures,  upon  compound  luxa- 
tions, &c. 

All  the  black  blood  formed  in  the  skin  goes  into  the 
general  venous  system  ; no  portion  belongs  to  the  abdo- 
minal. 

Nerves. 

Their  distribution  is  nearly  the  same  as  that  of  the 
blood  vessels.  Many  very  considerable  branches,  as 
different  divisions  of  the  musculo-cutaneous,  the  internal 
cutaneous,  the  lumbar,  the  saphena,  the  anterior  tibial,  the 
intercostals,  the  cervicals,  &c.  form  a kind  of  sub-cutaneous 
nervous  system,  from  which  go  all  the  branches  that  enter 
the  dermis.  These  branches,  in  passing  through  the  der- 
moid spaces  with  the  arteries  and  the  veins,  appear  to 
anastomose  often  together,  go  through  the  pores  which 
terminate  the  spaces  on  the  interior,  and  no  doubt  form 
the  papillae.  Observe  even  that  on  the  hand  where  the 
papillae  are  very  evident,  there  is,  in  proportion  to  the 
surface,  many  more  sub-cutaneous  nerves  than  any  where 
else. 

Msorbents. 

Many  absorbents  creep  under  the  skin  ; it  is  here  that 
they  can  be  the  most  easily  studied.  All  the  veins  are  sur- 
rounded with  them  ; various  fasciculi  are  observed  in  their 


DERMOID  SYSTEM. 


295 


interstices  ; so  that  a layer  of  absoi’bents,  arranged  in  the 
form  of  a continuous  layer,  seems  to  separate,  in  the  ex- 
tremities, the  aponeurosis  and  the  skin.  There  is  no 
doubt  that  the  origin  of  the  most  of  these  vessels  exists 
in  the  chorion,  that  they  carry  to  the  blood  the -fat  and 
the  cellular  lymph  of  its  spaces,  and  the  nutritive  matter 
of  its  fibres.  But  is  there  a particular  order  of  branches 
opening  upon  the  surface  of  the  epidermis  to  absorb  in 
certain  cases  foreign  substances  ? This  question  cannot 
be  answered  by  anatomical  inspection.  But  the  follow- 
ing considerations  appear  to  me  to  throw  great  light 
upon  it. 

1st.  The  sub-cutaneous  absorbents,  visible  by  injec- 
tions, are  too  numerous  in  proportion  for  the  mere  pur- 
pose of  carrying  back  the  fat  and  serum  of  the  neigh- 
bouring parts. 

2d.  There  are  many  medicines  which  appear  to  be 
evidently  absorbed  ; such  are  mercury  in  the  venereal  dis- 
ease, various  purgative  and  emetic  substances,  febrifuges 
even,  as  cinchona,  which,  when  applied  by  friction,  have 
produced  their  effects  as  well  as  if  taken  by  the  stomach  ; 
cantharides  often  act  upon  the  kidneys,  when  the  tincture 
is  used  as  a liniment,  narcotic  substances  sometimes  occa- 
sion a weight  in  the  head,  and  drowsiness  when  they  have 
been  externally  applied,  &e.  These  different  effects  are 
well  known  and  many  authors  have  given  examples  of 
them. 

3d.  There  is  we  know  absorption  of  different  kinds  of 
virus,  of  that  of  hydrophobia,  of  the  small-pox,  of  the 
venom  of  the  viper,  &c.  an  absorption,  it  is  true,  which 
rarely  takes  place  when  the  epidermis  is  whole,  but  which 
uniformly  does,  when  this  being  removed,  the  matter  is 
found  in  contact  with  the  external  capillary  net-work  of 
which  we  have  spoken.  I would  remark  even  that  the 
different  kinds  of  inoculation  of  the  small-pox,  of  the 
vaccine  disease,  &c.  evidently  prove  both  the  existence 


296 


DERMOID  SYSTEM. 


and  importance  of  this  net-work,  to  which  heretofore  suf- 
ficient attention  has  not  been  paid.  There  are  many  con- 
tagious principles  which  are  absorbed  through  the  epider- 
mis ; such  are  those  of  the  plague  which  the  clothes  com- 
municate and  those  of  different  pestilential  fevers  which 
penetrate  by  the  skin  more  than  by  respiration.  I believe 
cutaneous  absorptions  from  which  diseases  arise  may  be 
divided  in  the  following  way  ; 

('Ist,  local,  as  the  itch,  herpes,  tinea 
let.  Absorptions  which  take  place  | capitis,  &c.  &c. 
through  the  epidermis,  and  which-^  2d,  general,  as  pestilential  diseases, 
produce  an  effect  | putrid  fevers  taken  in  an  un- 

b healthy  place,  &c.  &c. 
pist,  local,  as  the  vaccine  disease, 
2d.  Absorptions  which  take  place  j the  small-pox,  Sio.  &c. 

only  when  the  epidermis  is  re- J 2d,  general,  as  hydrophobia,  the 
moved,  and  from  which  arises  j venom  of  the  viper,  a wound 
an  effect  | witli  an  instrument  impregnated 

b with  putrid  matter,  &c.  &c. 

We  see  by  this  table  that  the  absorbents  when  charged 
with  injurious  substances,  sometimes  do  not  transmit  them 
beyond  the  part  and  sometimes  carry  them  to  the  blood, 
which  conveys  them  to  the  different  organs  of  the  econ- 
ofny.  Some  authors  have  thought  that  in  those  cases  in 
which  the  effects  of  the  absorption  become  general,  there 
is  rather  nervous  action  and  sympathetic  phenomena,  than 
the  transmission  of  an  injurious  matter  into  the  circula- 
tion, and  that  consequently  the  solids  take  almost  an  ex- 
clusive part  in  these  diseases.  But  to  remove  all  doubt 
upon  this  point  it  is  sufficient  to  observe,  1st,  that,  in  the 
absorption  of  many  contagious  substances,  for  example, 
when  from  the  puncture  of  the  finger  with  a scalpel  im- 
pregnated with  putrid  substances,  a pain  is  produced, 
there  is  even  a redness  along  the  whole  course  of  the 
absorbents  of  the  arm,  and  the  axillar)^  glands  afterwards 
swell  ; 2d,  that  by  transfusing  into  the  veins  most  of  the 
substances  that  are  applied  in  frictions,  effects  analogous 
to  those  which  take  place  in  these  frictions  are  produced. 
Thus  purgatives  and  emetics,  transfused  or  absorbed,  act 


DERMOID  SYSTEM. 


297 


upon  the  intestines  and  stomach  the  same  as  if  introduced 
in  any  other  way.  It  seems  to  me  that  sufficient  use  has 
not  been  made  of  the  experiments  of  the  last  age  upon 
transfusions.  By  comparing  their  effect  with  that  which 
takes  place  upon  the  cutaneous  organ,  I think  that  it  is 
impossible  not  to  admit  a morbific  principle  in  the  blood, 
at  the  time  of  contagious  diseases. 

3d.  After  the  use  of  mercury  taken  in  frictions,  the 
emanations  of  this  metal  from  the  animal  fluids,  act  evi- 
dently upon  silver  when  placed  in  the  mouth,  the  rectum, 
&c.  I am  persuaded  even  that  the  blood  which  in  the 
natural  state  exerts  but  very  little  action  upon  this  metal, 
would  alter  it  then.  Accoucheurs  know  that  the  waters 
of  the  amnios  of  those  women  who  have  made  use  of 
mercurial  frictions  exhibit  the  same  phenomenon. 

4th.  Many  substances  that  are  not  medicinal  can  be 
transmitted  to  the  blood  by  cutaneous  absorption.  Water 
appears  to  enter  it  in  this  way,  in  the  rapid  production 
of  certain  dropsies,  in  those  cases  related  of  travellers, 
who  wanting  fresh  water  on  the  ocean,  have  in  part 
quenched  their  thirst  by  surrounding  themselves  with  damp 
clothes,  &c.  When  our  garments  are  impregnated  with 
the  oil  of  turpentine,  the  urine  soon  acquires  an  odour 
that  is  owing  to  the  principles  transmitted  to  the  blood  by- 
absorption.  Many  judicious  philosophers  have  asserted 
that  the  weight  of  the  body  has  been  increased  by  a walk 
in  the  morning. 

I have  observed  that  after  remaining  in  the  dissecting 
room  some  time,  the  intestinal  flatus  frequently  acquires 
an  odour  exactly  similar  to  that  which  the  bodies  in 
putrefaction  exhale.  In  the  following  way  I convinced 
myself  that  it  was  the  skin  as  much  as  the  lungs  that 
absorbed  these  odorous  particles.  I closed  my  nostrils, 
and  fitted  a long  tunnel  to  my  mouth,  which  passing  out 
of  the  window  allowed  me  to  breathe  the  external  air.  The 
flatus  from  my  bowels,  after  I had  remained  an  hour  in  a 
VOL.  III.  3S 


258 


DERMOID  SYSTEM. 


small  dissecting  room,  at  the  side  of  two  very  fetid  bodies, 
acquired  an  odour  nearly  similar  to  theirs.  I have  ob- 
served also  that  by  touching  for  a long  time  fetid  sub- 
stances, the  flatils  acquires  more  of  this  odour,  than  by 
remaining  only  in  an  air  loaded  with  cadaverous  exhala- 
tions. Then  the  absorbents  carry  at  first  these  exhala- 
tions to  the  blood,  which  afterwards  throws  them  out  by 
the  mucous  surface  of  the  intestines.  Thus  when  the 
urine  is  absorbed,  the  saliva,  the  mucous  juices,  &c.  have 
an  urinous  odour. 

I could  accumulate  many  other  proofs  of  cutaneous  ab- 
sorption ; but  I have  selected  only  the  principal.  Many 
others  have  been  cited;  Haller  in  particular,  to  whom  I 
refer,  has  multiplied  examples  of  it. 

I would  remark  however  that  cutaneous  absorptions 
have  a character  of  remarkable  irregularity  ; that  under 
the  same  apparent  influence,  they  sometimes  take  place 
and  sometimes  do  not.  It  is  thus  that  most  often  we  ab- 
sorb nothing  in  a bath,  that  we  escape  or  take  contagions, 
that  the  vaccine  disease  is  or  is  not  communicated,  that 
the  variolous  inoculation  is  also  often  uncertain,  &c.  This 
is  not  astonishing.  It  requires  a certain  degree  of  sensi- 
bility in  the  skin  for  the  absorption  of  this  or  that  sub- 
stance ; above  or  below  this  degree,  the  absorbents  repel 
this  substance.  Thus  in  the  intestinal  canal,  if  you  raise 
by  a purgative,  the  ordinary  degree  of  sensibility  of  the 
lacteals,  they  cease  immediately  for  a time  to  take  up 
drinks,  chyle,  &c.  and  every  thing  passes  off  by  the  anus. 
Now  a thousand  causes  act  incessantly  upon  the  skin;  a 
thousand  irritants  by  turns  applied  to  it  make  the  degree 
of  its  organic  sensibility  vary  every  instant,  increase, 
diminish  and  remove  it  from  that  which  is  necessary  for 
absorption.  Is  it  astonishing  then  that  this  function 
should  exhibit  so  many  varieties  ? Many  modern  phi- 
losophers have  produced  numerous  negative  facts  against 
cutaneous  absorption.  What  do  these  facts  prove  ? only 


DERMOID  SYSTEM. 


’399 


the  varieties  of  sensibility  which  I have  noticed  ; but  they 
do  not  destroy  the  mass  of  positive  facts,  generally  ac- 
knowledged and  which  together  form  a body  of  proof 
which  nothing  can  oppose.  Thus  we  have  seen  the  mu- 
cous surfaces  variable  in  their  vital  forces  on  account  of 
the  variety  of  their  excitants,  vary  also  in  their  absorp- 
tion. If  in  the  serous  membranes,  in  the  cellular  texture, 
in  the  work  of  nutrition  for  the  organs,  this  function  is 
uniform,  it  is  because  being  constantly  in  contact  with  the 
same  bodies,  the  surfaces  where  it  is  going  on  have  an 
uniform  degree  of  organic  sensibility. 

Many  facts,  in  relation  especially  to  contagions  seem  to 
prove  that  a state  of  weakness  is  favourable  to  cutaneous 
absorption.  1st.  Children  and  women  absorb  more  easily 
than  strong  and  vigorous  men.  2d.  Many  physicians 
have  observed  that  in  the  night  in  which  the  cutaneous 
organ  is  in  a state  of  remission  in  this  respect,  as  it  is  not 
stimulated  by  external  objects,  contagious  diseases  are 
more  easily  taken.  3d.  I have  remarked  that  most  of 
the  pupils  who  have  fallen  sick  during  my  dissections, 
had  carried  to  their  chambers  portions  of  subjects,  the 
emanations  from  which  had  been  able  to  affect  them  dur- 
ing sleep.  4th.  We  know  that  practitioners  recommend, 
that  persons  should  not  expose  themselves  to  contagious 
miasmata  during  hunger,  as  the  forces  are  then  languid  on 
account  of  the  emptiness  of  the  stomach. 

Exhalants. 

The  external  capillary  system  which  surrounds  the 
chorion  and  embraces  the  papillae,  appears  to  be  the  origin 
of  these  vessels,  as  it  is  the  termination  of  the  arteries  of 
the  dermoid  spaces.  The  exhalants  take  up  their  fluid 
there,  which  they  throw  out  upon  the  epidermis.  We 
have  no  anatomical  knowledge  as  to  their  form,  their 
length,  their  course  and  their  direction ; but  their  exist- 


300 


■DEiaioiD  sysTEir. 


ence  is  incontestibly  proved,  1st,  by  injections,  whicli  are 
sometimes  poured  out  upon  the  whole  cutaneous  surface  ; 
2d,  by  the  sanguineous  exhalation  which  takes  place  ill 
some  diseases  in  which  there  is  a real  bloody  sweat;  3d, 
by  the  natural  sweat  and  by  transpiration,  which  can  evi- 
dently have  no  other  agents,  though  some  authors  have 
admitted  that  there  were  certain  pretended  glands  for  the 
secretion  of  these  fluids. 

An  infinite  number  of  calculations  has  been  made  to 
ascertain  the  quantity  of  fluid  which  the  cutaneous  ex- 
halants  usually  pour  out.  We  are  dismayed  when  we 
read  the  result  of  the  labours  of  many  philosophers  upon 
this  point,  when  wm  go  over  the  calculations,  enormously 
multiplied,  of  Dodard,  Sanctorius,  Keil,  Robinson,  Royc, 
&c.  To  what  do  all  these  calculations,  for  ivhich  the 
life  of  a single  man  would  perhaps  be  insufficient,  tend  ? 
To  prove  to  us  that  when  we  start  from  a false  principle, 
the  whole  chain  of  consequences  drawn  from  it;  is  false, 
though  these  consequences  may  be  rigorously  deduced 
from  each  other.  In  fact,  most  philosophers  have  consid- 
ered the  skin  as  a kind  of  fountain  with  numerous  capil- 
lary lubes,  always  throwing  out  in  the  same  time  the 
same  quantity  of  fluids,  and  being  able  consequently  to 
be  subjected,  like  inert  capillaries  which  pour  out  fluids, 
to  proportions  and  calculations  of  quantity.  But  the'  re- 
sults of  these  calculations  have  soon  proved  how  mistaken 
their  authors  were.  Read  these  results,  and  you  will  see 
that  none  of  them  agree,  that  frequently  very  great  dif- 
ferences characterize  them.  Is  this  astonishing  ? A thou- 
sand causes  make  the  transpiration  vary  at  every  instant. 
Temperament,  exercise,  rest,  digestion,  sleep,  watchful- 
ness, the  passions,  &c.  increase  or  diminish  the  action  of 
the  cutaneous  exhalants.  I do  not  speak  of  the  difference 
from  climate,  s'easons,  &c.  which  is  still  more  decided. 

An  attempt  has  even  been  made  recently  to  ascertain, 
what  belongs  to  the  urine,  to  the  transpiration,  to  the  pul- 


DERMOID  SYSTEM. 


301 


monary  perspiration  and  to  the  excrements,  to  calculate  the 
relation  which  exists  between  the  quantities  thrown  out 
in  these  four  ways  ; useless  researches  ! We  miglit  obtain 
from  them  results  for  one  man,  w'hich  would  not  be  ap- 
plicable to  others.  Thus  see  if  we  have  ever  been  able 
to  make  a single  useful  application  to  physiology  or  patho- 
logy of  all  these  immense  labours  on  transpiration.  What 
would  you  say  of  a man  who,  during  the  days  of  the 
equinox,  in  which  the  state  of  the  atmosphere  was  every 
minute  changing,  should  try  to  establish  proportions  be- 
tween the  quantities  of  rain  which  fell  in  every  quarter 
of  an  hour,  or  of  one  who  endeavoured  to  fix  relations 
between  the  quantities  of  fluids  which  are  evaporated  in 
given  times,  from  the  surface  of  a vessel  under  \vhich 
the  intensity  of  the  heat  which  warmed  the  water  varied 
every  instant.  The  comparison  is  just.  We  might  be 
able  to  say  in  general,  at  the  end  of  a given  time,  nearly 
how  many  pounds  of  substances  went  from  the  body ; and 
yet  this  varies  in  every  individual.  But  to  attempt  to 
say  in  a general  manner  what,  in  this  common  quantity, 
the  urine  and  transpiration  separately  furnish,  is  to  prove 
that  w’e  do  not  understand  the  nature  of  the  vital  forces. 

We  have  already  observed,  that  all  our  knowledge 
upon  the  varieties  of  ti’anspiration,  is  reduced  to  some 
general  data ; that,  for  example,  in  cold  seasons  and 
climates,  it  is  by  the  internal  eniunctories  that  the  residue 
of  nutrition  and  digestion  principally  passes  oflT,  v/hilst  in 
warm  climates  and  seasons,  it  is  the  cutaneous  organ  that 
principally  throws  it  out. 

The  skin  on  the  one  hand,  and  the  kidneys  and  pul- 
monary surface  on  the  other,  are  then  in  this  respect,  in 
a constantly  inverse  activity.  Physicians  very  well  know 
this  difference  in  regard  to  the  urine  and  sweat ; they 
know  that  when  one  is  increased,  the  other  is  diminished  : 
that  in  winter  the  urine  contains  principles  of  various 
kinds,  and  that  in  summer  the  transpiration  has  a salt  taste 


302 


DERMOID  SYSTEM. 


and  other  peculiar  characters  which  it  owes  to  the  sub- 
stances which  are  foreign  to  it  in  the  first  season.  But 
they  have  not  so  well  examined  the  relation  of  the  tran- 
spiration with  the  sweat ; this  determined  me  to  make  the 
following  experiments : 

I wished  to  know  what  is  the  state  of  the  respiratory 
fluid  in  summer,  in  which  there  is  much  transpiration, 
and  in  which  all  the  heterogeneous  principles  consequent- 
ly go  out  by  the  skin.  To  obtain  this  fluid  which  is  ex- 
haled in  insensible  vapour,  I placed  a clean,  empty  bottle 
in  a pail  filled  with  ice  and  the  muriate  of  soda,  and  I 
respired  a long  time  in  it,  taking  care  not  to  allow  any 
saliva  to  fall  in.  The  parietes,  chilled  by  the  external 
ice,  condensed  into  small  icicles  the  vapour  of  my  breath, 
on  the  internal  surface  of  the  vessel.  When  I had  made 
a certain  quantity  of  these,  I "withdrew  the  bottle ; then 
by  putting  it  into  tepid  water,  the  icicles  immediately 
melted,  and  I had  in  a liquid  state  my  respiration,  which 
was  before  in  vapour.  Now  I have  been  struck  with  two 
things  in  this  experiment,  1st,  with  the  small  quantity  of 
fluid  that  I was  able  to  obtain,  though  I had  respired  for 
an  hour,  and  afterwards  made  two  men  respire  each  an 
hour  ; 2d,  with  this,  that  most  of  the  reagents  have  no 
action  upon  this  fluid.  Nitric,  sulphuric  and  muriatic 
acids,  lapis  infernalis,  and  alkohol  produce  no  effect  when 
mixed  with  it.  In  evaporating  a small  quantity  in  the 
concavity  of  a watch  chrystal,  no  residuum  is  left;  placed 
in  a spoon  over  the  flame  of  a candle,  it  experiences  no 
alteration  from  the  heat.  In  a word,  I have  been  almost 
tempted  to  believe  that  it  was  nothing  but  water.  I con- 
fess however  that  this  experiment  ought  to  be  carefully 
repeated. 

The  little  fluid  obtained  made  me  believe  that  the  form 
of  the  vessel  was  not  well  adapted  to  the  purpose,  because 
it  did  not  present  sufficient  surface  and  the  vapour  of  the 
lungs  was  too  little  divided.  I took  then  the  spiral  cylin- 


JJERMOID  SYSTEM. 


303 


der  of  a small  alembic  which  I surrounded  with  ice  in  a 
pail  ; I made  a man  breathe  through  it,  and  I obtained  in 
fact  more  fluid,  but  infinitely  less  however  than  I expect- 
ed, considering  the  great  cloud  that  is  formed  in  winter 
by  respiration.  In  an  hour,  two  ounces  of  fluid  only 
were  condensed,  which  I weighed  comparatively  with 
water,  and  found  a little  heavier,  a proof  that  some  prin- 
ciples are  mixed  with  its  aqueous  portion,  and  with  which 
I am  unacquainted. 

I am  convinced  that  in  winter  I should  have  condensed 
much  more  vapour ; the  inspection  of  an  animal  that 
breathes  proves  it  even,  as  I have  just  said.  I am  per- 
suaded also,  that  like  the  urine,  the  respiratory  fluid  is 
then  charged  with  principles  which,  during  summer,  pass 
off  by  the  skin,  though  I have  not  however  any  experi- 
mental data  upon  this  essential  point,  which  I propose  to 
clear  up  the  approaching  winter.  I think  even  that  many 
colds  depend  upon  this.  In  fact,  many  of  these  princi- 
ples thrown  out  by  the  mucous  surface  of  the  bronchia, 
not  soluble  in  the  air,  like  their  aqueous  vehicle,  stagnate 
upon  this  surface,  irritate  and  excite  a cough  which  throws 
them  ofi".  On  this  account,  we  cough  much  in  winter,  as 
w'e  have  often  occasion  to  bathe  in  summer,  when  the 
saline  substances,  which  are  accumulated  upon  the  skin 
by  the  exhalation  that  takes  place  there,  cannot  be  evap- 
orated by  the  air.  Hence  why  also  in  many  affections  of 
the  lungs,  in  which  the  mucous  glands  and  the  bronchial 
exhalants  do  not  increase  the  quantity  of  fluid  they  usually 
pour  out,  but  only  separate  with  it,  on  account  of  their 
change  of  organic  sensibility,  substances  which  the  air 
cannot  dissolve,  hence,  I say,  why  in  these  affections  there 
is  a constant  cough  ; for,  as  I have  said,  when  a substance 
remains  for  any  time  upon  the  mucous  s3^stem,  it  irri- 
tates, and  it  makes  an  effort  to  get  rid  of  it.  I believe 
that  this  elucidates  the  cause  of  manj"  coughs,  which  have 
been  considered  as  nervous,  on  account  of  the-  small  quan- 


304 


DERMOID  SYSTEM, 


tity  of  expectoration,  and  which  are  only  a means  that 
nature  employs  to  supply  the  want  of  the  evaporation  of 
the  air. 

I think  that  physiologists  have  not  paid  sufficient  atten- 
tion, either  as  it  respects  the  bronchia  or  the  skin,  to  the 
part  which  can  be  evaporated,  and  to  that  which  cannot. 
Some  animals  seem  to  throw  out  more  of  these  princi- 
ples that  cannot  be  evaporated,  than  man  ; hence  why  it 
is  necessary  to  curry  horses  every  day,  and  even  to  bathe 
them  often,  in  order  to  cleanse  their  skins  which  the  air 
would  leave  dirty.  Fourcroy  and  Vauquelin  have  re- 
marked that  there  is  never  phosphate  of  lime  in  the  urine 
of  these  animals  ; this  substance  appears  to  pass  out  with 
the  sweat,  and  to  be  chrystalized  on  the  surface  of  the  skin, 
from  which  it  is  removed  by  friction  and  water.  I can 
hardl}^  conceive  how  the  hairs  can  be  the  eraunctories  of 
it ; it  appears  to  me  to  be  more  natural  to  think  from  an- 
alogy, that  it  is  by  the  sweat  that  it  escapes.  I presume 
that  the  rain,  in  the  natural  state  is  as  necessary  to  these 
animals  as  to  plants.  The  first  do  not  avoid  it ; many 
even  expose  themselves  to  it ; it  serves  as  a bath  for  them, 
removes  the  saline  particles  the  air  does  not  dissolve,  and 
washes  the  skin. 

The  cutaneous  exhalants  do  not  appear  to  be  every- 
where equally  abundant.  The  face  and  chest  contain 
many  of  them  ; we  sweat  easily  in  these  places.  On  the 
back  and  the  extremities  they  are  less  numerous.  It  is 
rare  that  we  sweat  on  the  palms  of  the  hands  and  the  soles 
of  the  feet.  Besides  this  varies  remarkably  in  different 
individuals.  I know  two  sisters,  belonging  to  a family  in 
which  phthisis  has  been  frequent,  whose  chests  are  how- 
ever v.  ell  formed,  and  who  have  never  liad  any  sign  of  an 
affection  of  the  lungs,  and  yet  when  they  are  vrarm  they 
always  sweat  from  the  chest.  We  know  that  in  some  the 
sweat  appeal's  most  usually  in  the  face,  and  in  otliers  on 
the  cranium. 


DERMOID  SYSTEM, 


305 


Have  the  nerves  any  influence  upon  the  cutaneous  ex- 
halation ? In  many  cases  of  paralysis,  the  patients  sweat 
from  the  sound  side.  I have  attended,  for  two  months 
past,  a man  at  the  Hotel  Dieu,  who  after  an  apoplexy, 
had  hemiplegia  so  that  the  left  side  of  the  body  was  im- 
moveable, and  who  only  sweats  from  this  side,  so  that 
an  evident  line  of  demarcation  is  visible  the  whole  length 
of  the  median  line.  On  one  side,  the  skin  is  dry,  and 
on  the  other  it  is  very  moist.  I know  cases  are  related 
in  which  opposite  phenomena  have  taken  place  ; but  they 
do  not  destroy  the  observation  that  is  uniformly  made, 
that  the  sweat  takes  place  equally  upon  the  sound  and 
the  diseased  side.  Besides,  who  does  not  know  that  when 
the  nervous  action  is  annihilated  in  a limb,  a blister  acts 
upon  it  as  usual  ? Do  convulsions,  in  which  the  nervous 
action  is  so  much  raised,  increase  cutaneous  exhalation  ? 
Have  the  states  of  extreme  sensibility,  in  which  all  the 
cutaneous  nerves  are  so  susceptible  of  receiving  all  im- 
pressions, the  least  known  influence  upon  sweating  ? Let 
us  acknowledge  then  that  in  cutaneous  exhalation,  as  in 
secretion,  we  know  nothing  of  the  nature  of  the  nervous 
influence,  if  it  does  exist. 

Sebaceous  Glands. 

Besides  the  insensible  transpiration  and  the  sweat, 
which  are  thrown  out  by  the  skin,  this  organ  is  con- 
stantly lubricated  by  an  oily  fluid,  which  occasions,  when 
coming  out  of  a bath,  the  water  wdth  which  it  does  not 
unite,  to  collect  in  small  drops  upon  the  body,  which 
greases  the  linen  when  it  remains  too  long  in  contact  with 
the  skin,  catches  the  dust  that  is  floating  in  the  air,  makes, 
it  remain  upon  the  skin,  and  retains  many  foreign  sub- 
stances coming  with  the  sweat  from  without  or  within. 

This  fluid  is  in  general  much  more  abundant  in  negroes, 
whose  skin  is  on  this  account  disagreeable,  than  in  Eu- 
ropean nations  in  whom  it  abounds  especially  in  places 
VOL.  III.  39 


306 


DERMOID  SYSTEM. 


provided  ■with  hair,  particularly  on  the  cranium.  If  left 
Avithout  dressing,  the  hair  becomes  greasy,  unctuous  and 
shiny ; it  seems  even  that  this  abundance  of  oily  fluid  is 
destined  to  support  their  suppleness.  Thus  art  imitates 
nature  in  the  preparation  of  it,  and  greasy  substances 
almost  always  enter  into  the  dressings  of  the  toilet.  It 
appears  that  there  is  less  of  this  fluid  in  other  parts  where 
there  are  hairs.  It  oozes  in  very  small  quantity  from  the 
soles  of  the  feet  and  the  palms  of  the  hands,  no  doubt  on 
account  of  the  thickness  of  the  epidermis.  When  we 
wash  these  last,  the  water  collects  in  small  drops  on  the 
back  of  them,  and  not  in  the  palms,  which  are  easily  and 
uniformly  Avet ; there  is  never  any  of  it  deposited  on  the 
surface  of  the  nails.  This  cutaneous  oil,  retained  in  cer- 
tain places,  as  in  the  axilla,  the  perineum,  the  folds  of 
the  scrotum,  &c.  becomes  mixed  there  with  certain  prin- 
ciples of  the  transpiration,  and  often  exhales  a fetor  that 
is  almost  insupportable. 

This  oily  fluid,  of  the  nature  of  which  Ave  know  but 
little,  is  not  like  the  transpiration  or  the  fat  exposed  to 
evident  increase  and  diminution ; it  is  always  found  in 
nearly  the  same  proportion.  It  appears  to  preserve  the 
suppleness  of  the  skin,  by  preventing  it  from  cracking. 
The  ancients  sought  no  doubt  to  imitate  its  action  over 
the  Avhole  skin,  as  Ave  imitate  by  pomatum  its  functions 
in  regard  to  the  hair,  by  the  oily  unctions  which  they 
made  upon  the  body.  This  we  know  AA'as  much  prac- 
tised among  the  Romans. 

Whence  comes  this  cutaneous  oil  ? It  can  be  furnished 
from  three  sources,  1st,  from  transudation;  2d,  secretion; 
3d,  exhalation. 

Some  have  thought  that  the  sub-cutaneous  fat  oozed 
through  tlie  pores  to  form  it;  but  the  scrotum  which  is 
destitute  of  this  fat  is  one  of  the  most  oily  parts.  The 
skin  of  the  cranium,  which  is  so  to  the  highest  degree, 
is  hardh^  at  all  fatty.  That  of  the  cheeks  which  covers 


DERMOID  SYSTEM. 


307 


much  fat,  is  scarcely  lubricated  with  it,  &c.  In  emacia- 
tion the  skin  is  often  as  unctuous  as  in  corpulency,  though 
it  is  not  always  the  case.  Finally,  in  all  the  other  func- 
tions, physical  transudation  is  proved  to  be  nothing ; 
would  it  exist  then  here  alone  ? 

Those  who  admit  the  secretion  of  the  cutaneous  oil, 
(and  they  are  the  greatest  number,)  place  the  source  of 
it  in  the  small  glands  that  are  called  sebaceous,  and  which 
they  say  are  every  where  spread  under  the  skin.  We  see 
some  small  tubercles  upon  the  convexity  of  the  ear,  upon 
the  nose,  &c.  ; but  in  most  of  the  other  parts  it  is  impos- 
sible to  distinguish  any  thing  ; we  see  only  the  small 
eminences  of  which  I have  spoken  and  which  make  the 
skin  rough  ; now  they  have  nothing  in  common  with 
these  glands,  the  existence  of  which  I do  not  deny,  but 
vrhich  I confess  I have  many  times  in  vain  sought  for. 

This  has  made  me  think  that  there  is  perhaps  an  order 
of  exhalants  destined  to  separate  the  cutaneous  oil,  and 
which  is  distinct  from  that  of  the  exhalants  which  throw 
out  the  transpiratory  mattei’.  There  is  in  the  cellular 
texture  exhalants  for  fat  and  others  for  serum.  Certainly 
no  gland  presides  there  over  the  secretion  of  the  fat.  It 
is  the  same  with  the  marrow  which  the  exhalants  of  the 
medullary  membrane  furnish.  There  is  I think  as  much 
probability  in  the  supposition  of  the  exhalation,  as  of  that 
of  the  secretion  of  the  cutaneous  oil. 

Besides,  we  must  not  confound  this  oil,  either  with 
that  ceruminous  matter  which  certain  glands  pour  out  on 
the  edges  of  the  eyelids  and  behind  the  ears,  and  which 
is  forced  out  by  pressure  in  the  form  of  little  worms,  or 
with  that  whitish  substance  that  is  collected  between  tlie 
glans  and  the  prepuce,  and  which  is  so  evidently  furnished 
by  small  glands. 


30i 


DERMOID  SYSTEM. 


ARTICLE  THIRD. 

PltOPERTIES  OF  THE  DERMOID  SYSTEM. 


I.  Properties  of  Texture. 

These  properties  are  much  developed  in  the  skin. 
The  alternations  of  emaciation  and  corpulency  through 
which  our  organs,  the  limbs  especiall}^,  pass  sometimes 
from  a determinate  size  to  one  double  or  even  treble,  and 
afterwards  return  to  their  primitive  state,  prove  these 
properties  ; and  so  do  all  the  difierent  tumours,  deposits 
of  pus,  external  aneurisms,  sudden  engorgements  which 
accompany  great  contusions,  aqueous  collections  in  the 
abdomen,  pregnancy,  scirrhi,  numerous  affections  which 
increase  the  size  of  the  testicle,  hydrocele,  &c.  We  see 
in  all  these  cases  the  skin  at  first  extended  and  dilated, 
then  contracting  when  the  cause  of  the  distension  has 
ceased,  and  occupying  the  place  in  which  it  v>?-as  origi- 
nally circumscribed. 

The  remarkable  separation  which  the  two  edges  of  a 
wound  experience,  that  is  made  by  a cutting  instrument, 
is  owing  to  the  contractility  of  texture.  This  separation 
which  takes  place  upon  the  dead  body,  proves  what  we 
have  already  often  remarked,  viz.  that  the  properties  of 
texture,  absolutely  inherent  in  the  organic  texture,  are  for- 
eign to  the  vital  forces  from  which  they  only  borrow  an 
increase  of  energy  ; thus  the  cutaneous  retraction  is  much 
stronger  during  life  in  a longitudinal  or  transverse  wound. 
But  it  is  particularly  in  amputation  that  we  observe  this 
increase  of  contractility  from  the  vital  action.  No  part, 
not  even  the  muscles  retract  so  much  as  the  skin ; hence 
the  precept  so  much  recommended  in  this  operation  of 
saving  the  integuments  as  much  as  possible  ; hence  the 


DERMOID  SYSTEM. 


309 


essential  modifications  that  have  been  made  in  the  ancient 
methods.  The  muscular  retraction  is  more  sudden  ; but 
this,  which  is  more  durable,  ultimately  prevails  ; so  that  in 
the  ancient  mode  of  amputation,  where  every  part  was  cut 
at  the  same  level,  they  had  a conical  stump,  the  summit 
of  which  was  formed  by  the  bone,  in  which  was  next  seen 
the  muscles,  arteries,  &c.  and  in  which  the  skin  repre- 
senting the  base,  terminated  on  the  side  of  the  limb. 

There  are  however  many  cases  in  which  the  dermoid 
extensibility  is  less  than  it  at  first  seems  to  be.  For  ex- 
ample, in  large  sarcoceles,  the  skin  of  the  neighbouring 
parts  of  the  scrotum  being  drawn,  is  applied  upon  the 
tumour,  and  makes  up  for  the  extensibility  that  is  want- 
ing in  the  skin  of  this  part ; that  of  the  penis  especially 
is  almost  wholly  employed  to  cover  the  tumour ; so  that 
this  organ  disappears.  It  is  to  the  limits  placed  to  the 
Cutaneous  extensibility  that  must  also  be  referred  the  fol- 
lowing phenomenon  ; in  a wound  with  loss  of  substance, 
the  fleshy  granulations,  in  contracting  by  the  evacuation 
of  the  white  substance  that  filled  them,  draw  the  neigh- 
bouring skin  in  order  to  cover  the  wound  ; now  this 
drawing  produces  not  only  an  extension  but  a real  loco- 
motion. Hence  why  when  the  skin,  naturally  tense  and 
adherent,  cannot  yield  to  this  locomotion,  the  cicatrices 
are  formed  with  so  much  difficulty,  as  we  see  upon  the 
cranium,  the  sternum,  &c.  ; why  on  the  contrarj^  on  the 
scrotum,  the  fold  of  the  axilla,  &c.  they  take  place  with 
so  little ; why  in  dissecting  out  tumours,  it  is  so  much 
recommended  to  save  the  sound  integuments,  &c. 

When  the  skin  is  stretched,  the  fibres  which  compose 
the  spaces  that  have  been  spoken  of,  separate  from  each 
other,  and  these  spaces  become  broader.  ' Their  breadth 
becomes  especially  evident  on  the  internal  surface  of  the 
dermis  ; for  as  all  the  poies  of  the  external  surface  pierce 
obliquely  its  texture,  the  distension  of  this  texture  only 
diminishes  the  length  of  the  small  canal  they  form,  but 


310 


DERMOID  SYSTEiM. 


tloes  not  enlarge  the  orifice  of  it ; thus  whilst  the  internal 
surface  contains  interstices  of  considerable  size,  this  I’e- 
mains  uniform,  but  allows  us  to  see  these  interstices, 
which  render  it  more  transparent  where  they  exist ; hence 
that  appearance  like  marble  on  the  skin  of  the  abdomen 
of  women  who  have  had  many  children. 

When  the  skin  is  contracted,  the  internal  spaces  are 
drawn  together  and  even  effaced.  The  external  surface 
which  has  none  of  these,  cannot  diminish  so  much  in 
breadth,  so  that  there  is  a disproportion  in  the  breadth  of 
the  internal  and  external  surface ; hence,  as  I have  said, 
the  convexity  of  the  latter  in  the  horny  hardening  pro- 
duced by  boiling  water ; hence  also  the  inequalities  and 
external  roughness  which  takes  place  when  cold  acts 
powerfully  upon  us,  and  which  contracts  the  dermoid  tex- 
ture. Besides,  this  phenomenon  only  takes  place  when 
the  contractility  is  evident  in  the  ordinary  state ; for  if 
there  has  been  previous  distention,  the  cells  alread)^  en- 
larged, return  only  in  contracting  to  their  natural  state, 
and  there  is  no  disproportion  in  the  extent  of  the  internal 
and  external  surfaces  of  the  skin. 

In  most  of  the  extensions,  there  is  a diminution  of  the 
thickness  of  the  dermoid  texture.  It  is  only  when  it  is 
dilated  by  the  infiltration  of  water  in  its  spaces,  as  in  leu- 
cophlegmasia,  that  it  increases  in  thickness  by  diminish- 
ing in  density.  In  chronic  inflammation,  in  engorge- 
ment, and  in  various  alterations  of  which  the  dermoid 
texture  is  the  seat,  it  loses  in  part  the  faculty  of  stretch- 
ing ; it  breaks  with  ease  when  it  is  distended.  This  is 
what  happens  in  some  aneurisms,  in  those  of  the  aorta 
especially  that  have  produced  an  absorption  of  the  ster- 
num. A slow  inflammation  seizes  upon  the  skin  that 
covers  the  tumour,  and  it  breaks  with  a degree  of  disten- 
tion infinitely  below  what  it  bears  in  a sound  state,  if  the 
death  of  the  patient  does  not  prevent  this  fatal  rupture, 
two  examples  of  which  I have  seen  in  the  wai'd  of  lying 


DERMOID  SYSTEM. 


311 


in  women  at  the  Hotel  Dieu.  In  this  state  of  inflamma- 
tion, the  distention  is  very  painful,  whilst  it  is  not  so  in 
the  ordinary  state. 

The  skin  loses  also  its  contractile  power  in  most  of  the 
chronic  affections  of  which  it  is  the  seat,  and  which  alter 
its  texture. 

Are  there  some  days  in  which  the  skin  is  more  contract- 
ed, and  others  in  which  it  is  looser  and  more  expanded  ? 
I believe  so,  from  observing  the  marks  left  after  small- 
pox, which  are  much  more  apparent  and  deeper  some  days 
than  others. 

II.  Vital  Properties. 

These  are  strongly  marked  in  this  system.  We  might 
say,  that  nature  by  giving  an  excess  of  life  to  this  dermoid 
covering,  has  wished  to  establish  a striking  line  of  de- 
marcation, and  to  make  us  perceive  the  difference  between 
the  inorganic  bodies  with  which  its  external  surface  is  in 
contact,  and  the  organized  textures  that  its  internal  sur- 
face covers.  I shall  consider  these  vital  properties  as  in 
all  the  other  systems  ; some  belong  • to  animal  life  and 
others  to  organic. 

Properties  of  Minimal  Life. 

The  animal  sensibility  exists  in  the  highest  degree  in 
Uie  skin.  It  presides  over  the  feeling,  which  is  more 
acute  and  delicate  there  than  in  most  of  the  other  tex- 
tures. It  is  also  the  cause  of  touch,  a double  function 
which  is  very  different. 

The  feeling  is  the  faculty  of  perceiving  the  impression 
of  the  surrounding  bodies.  It  gives  us  the  sensations  of 
heat  and  cold,  moisture  and  dryness,  hardness  and  soft- 
ness, &c.  It  has  relation  then,  1st,  to  the  existence  ; 2d, 
to  the  general  modifications  of  external  bodies.  Its  ex- 
ercise precedes  that  of  all  the  other  senses  which  cannot 


312 


DERMOID  SYSTEM. 


be  exercised  until  after  its  action.  It  is  necessary  to  the 
sight,  to  hearing,  smelling  and  the  taste,  as  it  is  to  the 
touch.  It  depends  only  upon  a particular  modification  of 
the  animal  sensibility  ; it  is  nothing  but  this  property 
considered  in  exercise.  Thus  when  the  particular  modi- 
fications of  this  sensibility  which  preside  over  the  other 
senses  have  been  destro)md,  when  the  eye  is  insensible 
to  light,  the  ear  to  sounds,  the  tongue  to  tastes  and  the 
pituitary  membrane  to  odours,  these  different  organs  still 
preserve  the  faculty  of  feeling,  both  the  presence  of  bodies 
and  their  general  attributes. 

The  touch  has  only  relation  to  the  particular  modifica- 
tions of  bodies  ; it  is  the  source  of  our  notions  upon  their 
external  forms,  their  dimensions,  size,  direction,  &c.  It 
differs  essentially  from  the  four  other  senses. 

1st.  In  this,  that  it  does  not  require,  like  the  feeling, 
any  particular  modification  of  sensibility.  The  hand  is  a 
little  more  sensible  than  the  rest  of  the  skin  ; but  there 
is  not  a great  difference,  and  we  should  touch  bodies 
almost  as  well,  if  that  of  the  abdomen  covered  the  pha- 
langes. On  the  contrary,  each  sense  has  a peculiar  sensi- 
bility which  places  it  exclusively  in  relation  with  a deter- 
minate body  in  nature.  The  pituitary  membrane  would 
be  struck  by  light  in  vain,  if  placed  at  the  bottom  of  the 
eye  like  the  retina;  the  palatine  membrane  if  it  lined  the 
nasal  fossae,  would  not  perceive  odours,  <&c. 

2d.  The  touch  is  exercised  only  upon  masses,  more  or 
less  considerable  parcels.  The  other  senses  are  bcougbt 
into  action  by  the  insensible  and  infinitely  multiplied  par- 
ticles of  bodies,  as  the  luminous,  savoury  particles,  &,c. 

3d.  Most  of  the  otlier  senses  do  not  require  the  previous 
exercise  of  the  will.  Odours,  light  and  sounds  strike 
upon  their  respective  organs,  and  often  produce,  without 
our.  attending  to  them,  their  respective  sensations.  It  is 
the  same  with  feeling  ; the  will  most  commonly  has  no 
part  in  it.  It  is  exercised  because  we  live  in  the  midst  of 


DERMOID  SYSTEM. 


313 


many  excitements.  We  do  not  most  often  seek  for  the 
causes  of  general  sensations  ; they  are  those  that  come 
and  act  upon  us.  On  the  contrary,  the  touch  requires  to 
be  produced  by  an  act  of  the  will.  It  is  exerted  in  con- 
sequence of  the  exercise  of  the  other  senses ; it  is  because 
we  have  seen,  heard  or  felt  an  object,  that  we  touch  it. 
We  confirm  or  correct  by  this  sense  the  notions,  which 
tlie  others  have  given  us.  Hence  why  it  is,  as  it  were, 
dependant  on  them.  The  more  they  are  contracted,  the 
less  frequently  is  it  exercised.  The  blind,  the  deaf,  &c. 
have  less  desire  to  touch  than  him,  who  has  all  his  sensi- 
tive gates  open  to  the  impression  of  external  bodies. 

4th.  Most  of  the  other  senses  require  a peculiar  struc- 
ture as  well  as  a peculiar  sensibility  in  the  organs  which 
compose  them.  On  the  contrary,  the  touch  only  requires 
a particular  form  in  its  organs.  Provided  that  these  have 
on  the  one  hand  animal  sensibility,  and  on  the  other  can 
embrace  by  many  points  external  objects,  they  can  dis- 
tinguish their  tangible  qualities.  The  touch  will  be  ob- 
scure if  we  grasp  bodies  in  one  or  two  directions  only  ; 
yet  it  will  take  place.  Thus  we  touch  with  the  hollow 
of  the  axilla,  the  bend  of  the  arms,  hams,  &c.  with  the 
lips  and  with  the  tongue.  Thus  the  elephant  touches  with 
his  trunk,  reptiles  by  twining  themselves  around  bodies, 
most  animals  with  their  snouts,  &c.  But  the  more  the 
points  of  contact  are  multiplied,  the  more  perfectly  is  the 
sense  exercised.  The  hand  of  man  is  in  this  respect  the 
most  advantageously  formed ; it  proves  that  he  is  better 
adapted  to  communicate  with  what  surrounds  him  than  all 
other  animals ; that  the  empire  of  his  animal  life  is  natu- 
rally much  more  extended  than  that  of  theirs  ; that  his 
sensations  are  more  accurate,  because  they  have  a means 
of  perfection  that  theirs  have  not ; and  that  his  intellec- 
tual faculties  are  destined  to  have  an  infinitely  greater 
sphere,  since  they  have  an  organ  infinitely  better  than 
theirs  to  perfect  them. 

VOL.  III. 


40 


314 


DERMOID  SYSTEM. 


The  sensibility  of  the  skin  resides  essentially,  as  we 
have  seen,  in  the  papillary  body  ; it  is  there  that  all  the 
great  phenomena  relative  to  sensation  take  place.  It  is 
this  portion  of  the  skin  that  truly  belongs  to  animal  life, 
as  the  reticular  body  is,  on  account  of  the  vascular  plexus 
that  forms  it,  the  portion  essentially  dependant  on  organic 
life.  The  chorion  being  as  it  were  passive,  remains 
foreign  to  every  kind  of  important  function,  and  serves 
only  for  a covering. 

The  extremely  acute  sensibility  of  the  papillary  body 
requires  a covering  to  defend  it  from  strong  impressions. 
This  covering  is  the  epidermis.  When  it  is  removed, 
every  touch  is  painful ; the  impression  of  the  air  even  is 
very  much  so  ; it  is  this  removal  of  the  epidermis  that 
produces  the  smarting  that  is  felt  when  a blister  is  taken 
off.  Observe  in  fact  that  smarting  is  a very  frequent  kind 
of  pain,  which  the  animal  sensibility  of  the  skin  occa- 
sions when  more  raised  than  usual.  This  term  * is  bor- 
rowed from  burns,  which,  when  they  are  only  to  a cer- 
tain extent,  acting  nearly  like  blisters,  lay  the  papillae 
bare  ; now  as  it  is  always  the  skin  which  is  exposed  to 
the  action  of  fire,  we  transfer  to  all  burnt  organs  the  ideas 
which  we  attach  to  the  word  smarting.  But  the  pain  is 
far  from  having  the  same  character  in  the  other  systems; 
this  peculiar  one  belongs  only  to  the  dermoid,  in  which 
it  takes  place  from  a burn,  erysipelas,  after  a blister,  &c. 
and  during  all  inflammations  that  have  their  seat  in  the 
reticular  body.  No  other  system  when  inflamed  gives  us 
this  sensation.  The  pain  is  thi’obbing  in  the  cellular ; it 
exhibits  a wholly  different  modification,  in  the  muscular, 
when  it  is  the  seat  of  acute  rheumatism,  &c. 

There  is  another  kind  of  pain  which  is  also  peculiar  to 
the  cutaneous  system  ; it  is  itching,  which  is  the  first 

* In  order  to  understand  this  sentence  it  should  be  observed  that  the 
ivord  which  I have  translated  smarting  is  cuisson^  which  means  the 
action  of  fire  upon  animal  bodies,  and  is  also  used  for  the  painful  sensa- 
tion which  this  action  produces. — Tr. 


DERMOID  SYSTEM. 


'315 


degree  of  smarting.  We  remove  it  by  a gentle  friction, 
which  exciting  in  the  papillae  a different  sensation,  effaces 
that  of  which  they  are  then  the  seat ; but  when  this  new 
sensation  has  passed  off,  the  former  one,  which  is  occa- 
sioned by  a permanent  cause,  is  reproduced  and  requires 
a new  friction  ; there  happens  then  in  a small  way,  what 
we  observe  in  a large  one,  when  a stronger  pain  makes 
us  forget  one  that  is  weaker.  No  other  system  in  the 
economy  exhibits  this  kind  of  pain,  so  frequent  in  itch, 
herpes  and  many  other  cutaneous  eruptions.  In  their 
tubercular  inflammations,  the  serous  membranes  become 
the  seat  of  white  eruptions,  analogous  to  many  of  those 
of  the  skin  ; the  mucous  surfaces  are  also  often  affected 
with  many  small  pimples  ; now  this  sensation  is  never 
manifested  in  either  of  them. 

There  is  ako  a sensation  which  appears  to  be  the  mini- 
mum of  that  pain  of  Avhich  smarting  is  the  maximum  ; 
it  is  tickling,  a mixed  sensation,  an  hermaphrodite,  as  an 
author  has  called  it,  which  is  agreeable  when  carried  to 
a certain  degree  and  painful  beyond  it.  Carry  the  fingers 
lightly  over  a mucous  or  serous  surface,  a muscle  or  a 
nerve  laid  bare ; an  analogous  sensation  will  never  arise 
from  the  contact. 

The  animal  sensibility  of  the  skin  is,  like  that  of  the 
mucous  surfaces,  subjected  to  the  essential  influence  of 
habit,  w’hich  can  transform  successively  into  indifference 
or  even  into  pleasure,  what  was  at  first  painful.  Every 
thing  that  surrounds  us  furnishes  constant  proof  of  this 
assertion.  The  air  in  the  succession  of  the  seasons,  calo- 
ric in  the  numerous  varieties  of  the  atmosphere,  in  the 
sudden  change  from  one  temperature  to  another,  water  in 
a bath,  in  the  moist  vapours  with  which  the  medium  is 
loaded  in  which  we  live,  our  garments  of  which  some,  as 
those  of  wool,  are  at  first  very  painful,  every  thing  which 
acts  upon  the  skin  by  mere  contact,  produces  sensations 
In  it  which  habit  continually  modifies.  Observe  the  mode 


316 


DERMOID  SYSTEM. 


of  dress  of  different  nations ; in  some,  all  the  superior 
extremities  are  bare ; in  others,  the  fore-arm  only  ap- 
pears ; the  inferior  extremities,  either  in  whole  or  part, 
are  naked  in  others  ; in  some,  a more  or  less  considerable 
portion  of  the  trunk  is  left  exposed  to  the  air,  and  among 
the  savages,  nothing  is  covered.  The  portions  which  in 
each  people  remain  naked,  bear  the  contact  of  the  air, 
without  giving  any  painful  sensation.  Let  them  expose,  on 
the  contrary,  parts  usually  covered,  especially  if  it  is  cold, 
and  at  first  pain  will  be  the  consequence  of  it ; then  the 
parts  gradually  becoming  accustomed  to  this  contact,  will 
get  to  be  insensible  to  it.  There  has  been  much  said 
latterly  of  the  danger  of  the  Grecian  costumes,  of  the 
nudity  of  females,  &c.  I do  not  speak  of  the  morality  of 
them  ; but  every  thing  that  is  reprehensible  physiologi- 
cally is,  that  the  progress  of  the  fashion  has  been  more 
rapid  than  that  of  the  sensibility.  If  they  had  exposed 
at  first  the- neck,  then  a little  of  the  chest,  then  the  bosom,^ 
&c.  habit  would  by  degrees  have  given  a new  modifica- 
tion to  this  property,  and  no  accident  would  have  resulted 
from  it.  But  in  going  suddenly  from  a costume  in  which 
every  part  is  covered,  to  that  in  which  the  superior  half 
of  the  chest,  either  before  or  behind,  remains  naked,  is  it 
astonishing  that  colds,  catarrhs,  &c.  should  be  the  result 
of  it? 

Habit  extends  its  empire,  in  relation  to  the  skin,  even 
to  our  manners  themselves.  Decency  is  in  this  respect 
a thing  of  comparison.  An  Indian  woman,  with  nothing 
but  a narrow  cloth  around  the  pelvis,  would  be  with  us 
an  object  at  which  the  public  modesty  would  be  shocked. 
The  habit  of  mankind  serves  her  as  a veil  in  her  own 
country.  A female  savage  transported  entirely  naked  to 
the  same  country,  would  be  indecent  there  ; she  is  not  so 
in  her  own.  Observe  our  fashions  in  their  rapid  succes- 
sion ; a woman,  who  by  not  changing  her  costume,  would 
have  had  two  years  since,  that  of  a courtezan,  would  now 


DERMOID  SYSTEM. 


317 


lind  herself  dressed  with  great  modesty.  Indecency  in 
costume  is  that  merely  which  shocks  our  habit.  The 
female  Indian,  with  the  rag  that  covers  only  a quarter  of 
her  body,  is  more  decent  than  the  woman  in  whom  a 
small  opening  separated  the  neck-handkerchief  in  our  old 
fashions.  The  sight  of  the  face  shocks  those  people  among 
whom  females  are  vpiled.  Let  us  consider  then  habit  as 
the  type  of  the  decency  of  costumes.  Nature  has  wished 
in  physiology,  that  the  phenomena  over  which  it  presides, 
should  be  slowly  connected ; it  is  the  same  in  morals. 
The  woman  who  suddenly  changes  her  dress  from  one 
that  is  close  to  one  that  is  not,  exposes  herself  to  painful 
sensations,  to  catarrhal  diseases,  &c.  and  shocks  the  eyes 
of  those  who  had  been  accustomed  to  see  her  in  a differ- 
ent exterior.  When  the  change  is  gradually  and  insen- 
sibly brought  about,  neither  health  nor  morals  are  affected. 

Habit  does  not  modify  the  cutaneous  sensibility  which 
arises  from  an  alteration  of  texture,  from  an  inflammation, 
&c.  Powerfully  raised  in  this  last  state,  it  is  much  above 
its  natural  level.  Then  the  least  contact  becomes  ex- 
tremely painful ; thus  the  skin  is  no  longer  then  in  a state 
to  exercise  the  sense  of  feeling.  The  touch  itself  does 
not  distinguish  general  sensations.  All  bodies  make  a 
common  and  uniform  impression,  it  is  that  of  pain. 

The  animal  sensibility  of  the  skin  sometimes  dimin- 
ishes and  even  disappears ; paralysis  is  a proof  of  this. 
These  affections,  more  rare  than  the  loss  of  motion,  often 
however  take  place.  In  the  organs  of  the  senses,  it  is 
the  eye  which  most  frequently  loses  the  sensation  ; the 
ear  comes  next,  then  the  skin,  then  the  nostrils  and  finally 
the  tongue,  which  is  the  sensitive  organ  that  is  always 
most  rarely  paralyzed,  no  doubt  because  it  is  that  which 
is  the  most  connected  with  the  support  of  organic  life, 
without  which  we  could  not  exist.  The  others  belong 
especially  to  animal  life,  which  we  can  lose  in  part  with- 
out ceasing  to  exist. 


SIS 


DERMOID  SYSTEM. 


The  whole  skin  is  never  at  the  same  time  paralyzed  ; 
there  is  rarely  even  hemiplegia  in  this  respect ; the  feel- 
ing is  not  extinguished  but  in  an  insulated  part.  I would 
remark  that  the  existence  of  these  paralyses  is  also  a 
proof  of  the  want  of  nervous  influence  upon  cutaneous 
exhalation  and  the  capillary  circulation,  since  both  go  on 
very  well  in  this  case  as  well  as  in  paralysis  of  motion,  as 
I have  observed  above.  Cut  the  nerves  of  a limb  of  an 
animal,  in  order  to  render  this  limb  insensible  ; if  after 
this  you  apply  an  irritant,  the  skin  will  inflame  as  usual. 

When  the  animal  sensibility  is  in  exercise,  is  there  a 
kind  of  erection  of  the  papillae  that  they  may  feel  more 
acutely  ? The  same  observation  may  here  be  made  as  was 
in  regard  to  the  mucous  surfaces.  This  erection  is  an  in- 
genious idea  of  some  physicians,  and  not  a fact  which 
rests  upon  observation.  I even  think  that  this  contra- 
dicts it ; for  examined  with  a glass  the  papillae  appear  to 
be  constantly  in  the  same  state.  Why  should  not  the 
skin  feel  like  a nerve  laid  bare,  like  the  eye,  the  ear,  &c. 
in  which  these  sorts  of  erections  have  never  been  ima- 
gined ? 

Animal  contractility  is  wholly  foreign  to  the  cutaneous 
organ,  which  moves  voluntarily  only  by  the  influence  of 
its  fleshy  pannicle. 

Properties  of  Organic  Life. 

Organic  sensibility  and  insensible  contractility  exist  in 
the  highest  degree  in  the  cutaneous  organ.  The  external 
capillary  system,  which  forms  the  reticular  body,  is,  as  I 
have  said,  especially  the  seat  of  these  properties.  They 
are  in  constant  activity  in  order  to  preside,  1st,  over  the 
capillary  circulation  ; 2d,  over  exhalation  ; 3d,  over  ab- 
sorption ; 4th,  over  the  nutrition  of  the  whole  dermoid 
texture  ; 5th,  over  the  secretion  of  the  cutaneous  oil,  if 
tlie  sebaceous  glands  exist.  It  is  not  astonishing  that 


DERMOID  SYSTEM. 


319 


these  properties  should  be  so  much  developed  in  the  skin, 
in  which  they  have  so  many  functions  to  support.  Add 
to  these  considerations  the  constant  action  of  external 
bodies,  an  action  which  keeps  this  organ  in  continual 
excitement,  which  incessantly  stimulates  its  sensibility, 
which  is  to  this  sensibility  what  that  of  the  bodies  con- 
tained in  the  mucous  surfaces  is  to  the  sensibility  of  these 
surfaces ; the  irritation  is  even  more  sensible,  because  the 
stimuli  are  oftener  changed.  A thousand  agents  of  nature, 
of  different  density  and  composition  continually  succeed 
each  other  on  the  exterior  of  the  body,  and  at  tbe  same 
time  that  they  act  upon  the  animal  sensibility  of  the  skin, 
to  produce  various  sensations,  they  excite  the  organic  sen- 
sibility in  order  to  support  the  functions  over  which  this 
sensibility  presides. 

Is  it  astonishing  then  that  the  greater  number  of  cuta- 
neous diseases  supposes  an  alteration  in  this  property 
and  in  the  insensible  organic  contractility  which  is  not 
separated  from  it  ? I divide  these  diseases  into  four  classes, 
according  to  the  structure  we  have  distinguished  in  the 
skin. 

1st.  There  are  diseases  of  the  papillae;  these  are  the 
paralyses  and  various  kinds  of  increase  of  feeling,  which 
reside  only  in  the  nerves.  Women  are  especially  subject 
to  these  last,  which  are  so  great  in  some  nervous  affec- 
tions, that  mere  contact  of  the  skin  if  considerably  pow- 
erful produces  convulsions.  To  this  also  should  be  re- 
ferred the  extreme  susceptibility  of  some  individuals  in 
whom  tickling  produces  a general  revolution.  It  is 
necessary  to  distinguish  these  exaltations  of  animal  sen- 
sibility, from  those  of  which  we  have  spoken  above,  and 
which  depend  upon  inflammation.  The  organic  sensi- 
bility is  especially  affected  in  these  last;  we  might  say 
that  by  its  increase  it  is  transformed  into  animal  sensi- 
bility ; whereas  in  the  other  case  this  last  property  alone 
is  altered. 


320 


DERMOID  SYSTEM. 


2cL  There  are  diseases  which  have  evidently  their  seat 
in  tlie  cellular  texture  which  occupies  the  dermoid  spaces  ; 
such  are  the  inflammations  of  the  cutaneous  portion  which 
covers  a phlegmon,  a bile,  &c. 

3d.  There  are  diseases  of  the  external  capillary  net- 
work, from  which  the  exhalants  arise.  To  this  must  be 
referred  erysipelas,  many  species  of  herpes,  measles,  scar- 
latina and  many  acute  cutaneous  eruptions  that  are  daily 
met  with  in  practice. 

4th.  Finally,  there  are  diseases  in  which  the  chorion  is 
affected.  Elephantiasis,  and  in  general  many  chronic 
cutaneous  diseases  appear  to  me  to  be  of  this  number,  and 
1 will  even  observe  that  the  chorion  never  appears  to  be 
primarily  affected  in  acute  diseases.  The  obscurity  of  its 
vital  forces,  its  dense  and  compact  texture,  and  its  com- 
parative want  of  vessels  prevent  it  from  accommodating 
itself  except  to  chronic  affections.  In  phlegmonous  erysi 
pelas,  in  biles,  &c.  it  is  only  influenced,  but  it  is  not 
essentially  diseased.  Thus  we  have  seen  that  all  the  af- 
fections of  the  osseous,  cartilaginous,  fibrous,  fibro-carti- 
laginous  systems,  &c.  are  really  slow  and  chronic,  on  ac- 
count of  the  texture  and  the  vital  obscurity  of  these  sys- 
tems. 

Now  if  we  reflect  on  this  division  of  cutaneous  dis- 
eases, we  shall  see  that  except  those  of  the  first  class, 
w’hich  are  not  numerous  and  which  consist  in  greater  or 
less  alterations  of  animal  sensibility,  we  shall  see,  I say, 
that  all  the  others  suppose  a more  or  less  considerable 
affection  of  the  organic  sensibility  and  of  the  correspond- 
ing insensible  contractility.  All  are  derived  from  an  in- 
crease, a diminution  or  an  alteration  of  these  properties. 

It  is  also  to  the  different  clianges  of  tliese  properties, 
that  must  be  refez'red  the  more  or  less  copious  sweats  and 
the  various  exudations  of  which  the  skin  is  the  seat.  In 
fact,  tlie  exhalant  vessels  remain  alwa}^s  the  same  in  rela- 
tion to  their  sti'ucture.  Why  then  do  they  admit  a greater 


DERMOID  SYSTEM, 


321 


or  less  quantity  of  fluids  ? Why  at  certain  times  do  they 
aliovv  of  the  passage  of  substances,  which  they  repel  at 
others  ? It  is  because  the  modifications  of  their  organic 
forces  are  changed.  These  forces  are  often  weakened  in 
an  evident  manner  in  diseases  ; they  become  languid  and 
are  prostrated.  Then  blisters  are  applied  in  vain ; the 
organic  sensibility  no  longer  answers  to  the  excitement 
that  is  made  upon  it.  This  is  a striking  phenomenon  in 
ataxic  fevers,  and  proves  the  independence  of  the  pheno- 
mena of  cutaneous  exhalation,  capillary  circufation,  &c. 
in  regard  (o  the  cerebral  nerves.  In  fact,  whilst  during  the 
paroxysm  the  brain  is  in  extreme  excitement,  the  volunr 
tary  muscles  are  put  by  this  excitement  into  a violent 
state  of  convulsion,  and  the  energy  of  the  whole  of  the 
animal  life  seems  to  be  doubled  before  it  ceases  to  exist, 
the  organic  is  already  in  part  exhausted  ; the  functions  of 
the  portion  of  the  skin  which  belongs  to  this  life  have 
already  ceased. 

The  stimuli  of  cutaneous  organic  sensibility  vary  re- 
markably in  their  degree  of  intensity.  1st.  The  strong- 
est are  fire,  cantharides,  the  alkalies,  the  acids  sufficiently 
diluted  by  water  not  to  act  but  upon  the  vital  forces  and 
not  to  alter  the  dermoid  texture  by  the  horny  hardening, 
the  juices  of  many  acrid  and  corrosive  plants,  certain 
fluids  even  produced  in  the  economy,  as  those  of  cancers, 
&c.  All  these  stimuli  redden  the  skin  when  they  are 
applied  to  it.  2d.  Most  of  the  same  stimuli,  diminished 
in  intensity,  stimulate  it  but  slightl3^  3d.  Finally,  aque- 
ous fluids,  cataplasms  and  emollient  fomentations  seem  to 
produce  this  excitement  the  least ; they  even  rather 
weaken  the  cutaneous  organic  sensibility ; they  seem  to 
act  upon  it  like  sedatives  and  moderate  the  kind  of  excite- 
ment it  produces  in  inflammations.  The  same  is  true  of 
most  of  the  fatty  substances  ; thus  oils,  butter,  grease,  &c. 
are  in  general  not  calculated  to  keep  up  the  suppuration 
of  blisters.  It  is  requisite,  in  order  to  keep  the  skin  at 

VOL.  III.  4 1 


322 


DERMOID  SYSTEM. 


the  degree  of  organic  sensibility,  necessary  for  the  puru- 
lent exudation  that  then  takes  place,  to  mix  cantharides 
with  fatty  substances. 

The  skin  does  not  appear  to  enjo}?  sensible  organic  con- 
tractility. Stimuli  usually  produce  no  other  action  upon 
it,  than  the  contraction  imperceptible  to  the  eye,  which 
composes  insensible  contractility,  and  which  takes  place 
especially  in  the  small  capillary  vessels.  There  is  how- 
ever one  circumstance  in  which  this  contraction  is,  to  a 
certain  extent,  apparent ; it  is  when  cold  acts  briskly 
upon  the  skin,  which  it  wrinkles  into  goo~se  flesh,  as  it  is 
called.  I have  pointed  out  above  the  mechanism  of  this 
contraction,  of  which  the  chorion  is  the  seat,  and  which 
holds  a medium,  like  many  motions  which  I have  already 
had  occasion  to  notice,  between  the  two  species  of  organic 
contractility. 

Sympathies. 

We  shall  still  follow  the  division  of  the  sympathies 
into  active  and  passive,  a division  which  is  more  remarka- 
ble here  than  in  most  of  the  other  systems,  because  the 
sympathies  are  much  more  numerous. 

Passive  Sympathies. 

The  animal  sensibility  is  very  often  brought  into  action 
in  the  skin,  by  the  affections  of  the  other  systems.  We 
know  that  the  application  of  cold  to  the  sole  of  the  foot 
frequently  produces  affections  of  the  head  ; that  in  many 
cases,  the  different  species  of  itching,  and  even  of  smart- 
ing appear  without  an  injury  of  the  part  where  the  pain 
is  felt.  It  is  useless  to  cite  examples  that  are  known  to 
all  physicians.  I will  confine  myself  to  the  sympathies  of 
heat  and  cold  alone,  which  have  not  yet  been  spoken  of. 

I call  by  this  name  the  sensation  that  is  experienced 
upon  the  skin,  when  there  is  not  a superabundance  or 
absence  of  caloric  there.  There  is  evidently  a material 


DERMOID  SYSTEM. 


323 


cause  for  the  heat  in  inflammation  and  for  the  cold  in  the 
ligature  of  a great  artery.  On  the  contrary,  in  the  cases 
of  which  I spoke,  it  is  but  an  aberration  of  the  internal 
sensitive  principle,  which  resembles  that  which  takes 
place  when  we  refer  the  pain  to  the  extremity  of  an 
amputated  limb.  This  is  what  occurs  in  many  cases 
of  shivering,  in  which  the  internal  sensitive  principle 
refers  to  the  skin  a sensation  of  which  the  cause  does  not 
exist.  By  approaching  the  fire  then  we  do  not  become 
warm,  because  we  really  were  not  cold  ; but  we  only  de- 
stroy by  a real  sensation,  the  opposite  sensation  which  is 
illusory  that  we  experience,  or  rather  we  turn  the  per- 
ception from  this  sensation.  We  know  that  at  the  in- 
stant of  the  ejaculation  of  semen,  a sudden  and  sympa- 
thetic chill  often  extends  over  the  body.  We  know  the 
cold  of  fear,  which  almost  always  arises,  like  the  sweat 
produced  by  this  passion,  from  the  sympathetic  action 
exerted  upon  the  cutaneous  organ  by  an  epigastric  organ 
aflected  by  the  passion. 

Observe  what  takes  place  in  the  beginning  of  most  acute 
local  diseases,  as  in  those  of  the  serous  and  mucous  sur- 
faces, of  the  lungs,  of  the  gastric  viscera,  &c.  &c.  The 
organ  which  is  to  be  the  seat  of  the  disease  is  at  first 
affected ; immediately  many  sympathetic  and  irregular 
symptoms  arise  in  all  those  which  are  sound;  this  is  the 
affection  that  precedes.  When  the  disease  is  once  deve- 
loped, and  it  follows  its  periods,  a new  order  is  establish- 
ed, as  it  were,  in  the  economy.  The  relations  of  the 
organs  seem  to  change.  In  the  preternatural  irregularity 
of  the  functions^  a kind  of  regular  assemblage  of  symp- 
toms is  manifested,  it  is  this  assemblage  which  character- 
izes the  disease  and  distinguishes  it  from  every  other  in 
which  a different  order  of  morbific  relations  is  established 
between  the  functions  ; now  the  passage  from  the  natural 
to  the  preternatural  relation  of  functions  is  marked  by  a 
thousand  vague  symptoms,  which  should  be  attributed  to 


324 


DERMOID  SYSTExM. 


sympathies,  and  among  which  appears  particularly  the 
kind  of  shiver  in  of  which  I have  spoken. 

In  the  beginning  of  digestion  a kind  of  s}'mpathetic 
cold  is  also  referred  to  the  skin,  which  is  most  often  as 
warm  as  usual ; it  is  an  action  exerted  by  the  stomach 
upon  the  cutaneous  sensibility,  an  action  from  which 
arises  a particular  sensation,  different  no  doubt  from  that 
which  the  same  viscus,  when  disordered,  produces  in  the 
head,  occasioning  head-ache,  but  which  is  owing  how- 
ever to  the  same  principle. 

The  heat  is  very  often  sympathetic  in  the  cutaneous 
organ,  less  however,  as  I have  observed,  than  in  the  mu- 
cous system.  We  know  the  flushes  of  heat  that  so  often 
extend  over  the  skin  in  an  irregular  manner,  in  different 
fevers,  and  which  are  not  attended  with  a greater  disen- 
gagement of  caloric. 

Our  modern  philosophers  will  not  perhaps  be  able  to 
understand,  how  it  is  that  whilst  in  the  greatest  number 
of  cases,  the  application  of  a degree  of  caloric  superior  or 
inferior  to  that  of  our  temperature,  is  necessary  to  pro- 
duce heat  or  cold,  this  sensation  can  arise  in  a part  though 
it  may  not  have  experienced  an  increase  or  diminution 
of  this  principle.  But  in  the  greatest  number  of  cases 
has  not  pain  a material  cause  ? And  yet  all  sympathies 
produce  it  without  this  cause.  The  vulgar,  who  sto]j  at 
the  diversity  of  the  modifications  of  feeling,  believe  that 
an  insulated  principle  presides  over  each.  Let  us  dis- 
regard all  these  modifications,  in  order  to  see  but  a single 
principle  in  the  irregularities  as  in  the  regular  course  of 
sensibilit)''.  That  this  property,  sympathetically  altered, 
gives  us  the  sensation  of  heat  or  cold  as  in  the  skin,  of 
pulling  as  in  the  nerves,  of  lassitude  as  in  the  muscles 
in  the  beginning  of  a disease,  &c.  ; these  are  but  varieties 
of  a single  cause,  one,  of  which  we  are  ignorant,  but 
which  evidently  exists.  In  general,  the  sympathies  of 
animal  sensibility  put  into  action  in  each  system  the  sen- 


DERMOID  SYSTEM. 


326 


sation  which  is  usual  there.  The  sympathy  which,  act- 
ing upon  the  skin,  creates  there  a sensation  of  heat  or  of 
cold,  would  have  produced  that  of  lassitude  if  it  had  acted 
upon  a muscle. 

In  order  to  form  an  exact  idea  of  heat  and  cold  consid- 
ered as  sensations,  let  us  recollect  that  they  may  arise 
from  different  causes.  1st.  From  the  increase  or  diminu- 
tion of  the  caloric  of  the  atmosphere.  2d.  From  the  disen- 
gagement or  the  want  of  disengagement  of  this  fluid  in  a 
part  of  the  economy,  as  in  a phlegmon  or  after  the  liga- 
ture of  an  artery  of  a limb.  3d.  Sometimes  without 
previous  inflammation  more  caloric  is  disengaged  in  the 
whole  body  ; there  is  a general  increase  of  temperature  ; 
we  then  feel  an  internal  and  external  heat  ; or  caloric  is 
disengaged  locally  in  a part  of  the  skin,  and  the  patient 
feels  a heat  there  as,  he  does  w'ho  applies  his  hand  upon 
this  place.  4th.  Finally,  there  are  sympathies  of  heat  and 
cold.  Some  other  parts,  besides  the  mucous  surfaces  and 
the  skin,  feel  these  sympathies ; we  know  the  sensation 
of  coldness  that  is  felt  to  arise  from  the  abdomen  to  the 
thorax,  &c. 

The  organic  properties  of  the  skin  are  also  frequently 
put  into-  action  by  sympathies.  The  sweat  on  the  skin  is 
suppressed  in  a moment,  if  a cold  body  is  taken  into  the 
stomach.  The  entrance  of  teas  into  this  viscus,  and  an 
increased  cutaneous  exhalation,  are  two  phenomena  that 
take  place  almost  at  the  same  instant ; so  that  we  cannot 
refer  the  second  to  the  absorption  of  the  drink,  then  to 
its  passage  into  the  black  blood  through  the  lungs,  and 
afterwards  into  the  red  blood.  The  production  of  sweat 
is  then  here  analogous  to  its  suppression  in  the  preceding 
case  ; it  resembles  that  of  fear,  and  that  of  phthisis  in 
which  the  lungs  being  affected  act  upon  the  skin.  Shall 
I speak  of  the  innumerable  varieties  of  this  organ  in  dis- 
eases, of  its  dr}^ness,  its  moisture,  its  copious  sweats,  &c. 
phenomena  for  the  most  part  sympathetic,  and  which 


326 


DERMOID  SYSTEM. 


arise  from  the  relations  which  connect  this  sound  organ 
with  the  diseased  parts  ? I have  pointed  out  those  which 
exist  between  it  and  the  mucous  surfaces.  The  membrane 
of  the  stomach  is  the  one  with  which  it  especially  sym- 
pathizes. The  digestive  phenomena  are  a proof  of  this. 
It  would  he  necessary  to  treat  of  all  diseases  in  order  to 
speak  of  the  sympathetic  influences  exerted  upon  the  skin. 
These  influences  are  often  chronic.  How  in  many  or- 
ganic diseases,  do  different  tumours  form  upon  the  skin  ? 
Precisely  as  petechise,  miliary  eruptions,  &c.  are  produced 
in  acute  fevers ; the  difference  is  only  in  the  duration  of 
the  sympathetic  phenomena. 

Animal  and  sensible  organic  contractility  cannot  be 
evidently  put  into  action  in  the  passive  sympathies  of  the 
skin,  since  it  is  not  endowed  with  these  properties. 

Aclive  Sympathies. 

The  four  classes  of  cutaneous  affections  of  which  we 
have  spoken,  occasion  many  sympathetic  phenomena,  the 
following  ai’e  some  of  them. 

1st.  Whenever  the  papillae  are  strongly  excited,  as  in 
the  tickling  of  very  sensitive  people,  various  organs  feel 
it  sympathetically;  sometimes  it  is  the  heart;  hence  the 
syncopes  that  then  take  place ; sometimes  it  is  the  stomach ; 
thus  I knew  two  persons  who  could  be  made  to  vomit  by 
tickling  them  ; sometimes  it  is  the  brain,  as  when  in  very 
irritable  people,  tickling  is  carried  so  far  as  to  produce 
convulsions,  which  is  not  rmry  rare  in  nervous  women. 
Who  is  ignorant  of  the  influence  which  the  organs  of 
generation  receive  from  the  skin,  when  stimulated  in  dif- 
ferent parts  ? 

Physicians  are  often  astonished  at  the  extraordinary 
effects  which  some  mountebanks  produce  in  the  economy, 
who  know  how  to  profit  by  their  knowledge  of  the  cuta- 
neous sympathies  produced  by  tickling.  But  why  should 
we  be  more  astonished  at  these  phenomena,  than  at  the 


DERMOID  SYSTEM. 


327 


vomitings  produced  by  an  afiection  of  the  womb,  at  the 
diseases  of  the  liver  arising  from  an  injury  of  the  brain, 
or  at  hemicrania  the  seat  of  which  is  in  the  gastric  vis- 
cera ? The  only  difference  is  that  we  can  in  the  first  in- 
stance, produce  to  a certain  extent  those  sympathetic  phe- 
nomena, which  we  only  observe  in  the  other.  Why  do 
we  not  oftener  make  use  in  medicine  of  the  influence 
which  the  skin  when  tickled  exerts  upon  the  other  organs  ? 
In  hemiplegia,  in  adynamic,  ataxic  fevers,  &c.  who  knows 
if  the  excitement  of  the  sole  of  the  foot,  which  is  so  sen- 
sible, as  every  one  knows,  if  that  of  the  hypochondrium, 
which  is  not  less  so  in  some  people,  &c.  would  not  be 
better,  if  repeated  ten  or  twenty  times  a day,  than  the 
application  of  a blister,  the  irritation  of  which  soon  passes 
off?  Besides  you  would  never  obtain  by  a blister,  rube- 
facients, &c.  means  which  apt  as  much  and  more  upon 
the  organic  than  the  animal  sensibility,  an  effect  as  strik- 
ing, an  affection  as  general  in  the  sensitive  system,  as  by 
the  tickling  of  certain  parts,  a means,  which  acting  only 
upon  this  last  species  of  sensibility,  produces  phenomena 
exclusively  nervous ; whilst  the  exhalant  system  and  the 
capillary  with  red  blood  are  especially  affected  by  the 
others.  Certainly  there  are  cases  in  which  one  of  these 
means  is  preferable  to  the  other.  I propose  to  ascertain 
these  cases. 

We  have  not  yet  sufficiently  analyzed  the  different 
kinds  of  excitement  in  diseases ; we  have  not  endeavour- 
ed to  profit  enough  by  what  observation  has  taught  us, 
upon  the  sympathies  we  can  produce  at  will.  Might  we 
not  however  say,  that  nature  has  established  certain  rela- 
tions between  very  remote  organs,  that  we  may  be  able 
to  make  use  of  these  relations  in  our  means  of  cure  ? 
The  charlatan,  who  employs  external  tickling  for  certain 
nervous  affections,  is  often  more  rational,  without  know- 
ing it,  than  the  physician  with  all  his  pharmaceutical 
means. 


328 


DERMOID  SYSTEM. 


2d.  Whenever  the  cutaneous  exhalants  or  the  external 
capillary  system  from  which  they  arise,  are  affected  in 
any  manner,  many  other  parts  feel  it,  and  this  is  a second 
order  of  the  active  sympathies  of  the  skin.  Here  are  re- 
ferred a great  number  of  phenomena,  of  which  the  fol- 
lowing are  a part. 

A bath  which  acts  upon  the  skin  during  digestion, 
affects  sympathetically  the  stomach,  and  disturbs  this 
function.  When  this  viscus  is  agitated  by  spasmodic 
motions,  oftentimes  the  influence  which  it  receives  from 
it  suddenly  calms  it,  and  brings  it  to  its  ordinary  state. 
Not  long  since  in  my  evening  visit  at  tfie  Hotel  Dieu,  I 
saw  a woman  who  was  vomiting  continually  from  a sud- 
den suppression  of  her  catamenia.  I directed  sedatives 
which  were  useless.  The  next  evening  she  was  in  the 
same  state  ; I had  her  put  into  a bath  ; every  thing  was 
calmed  the  moment  she  came  out  of  it,  and  yet  the  cata- 
menia did  not  return.  Few  organs  are  more  dependant 
on  the  skin  than  the  stomach. 

The  action  of  cold  upon  the  cutaneous  organ  produces 
many  sympathetic  effects,  especially  when  this  action 
takes  place  while  we  are  sweating.  The  term  repercus- 
sion of  transpiration  is  not  proper  to  express  what  then 
takes  place  ; it  gives  a very  inaccurate  idea.  Let  us  sup- 
pose that  a pleurisy  arises  from  cold  suddenly  applied, 
the  following  is  what  happens  ; the  organic  sensibility  of 
the  skin  being  immediately  altered,  that  of  the  pleura  is 
sympathetically  altered.  By  it  the  exhalants  become  in 
relation  with  the  blood  ; they  admit  it  instead  of  the 
serum  which  they  before  received,  and  inflammation  super- 
venes. Thus  this  phenomenon  is  the  same  as  that  in 
which  the  application  of  a cold  body  upon  the  skin  sud- 
denly arrests  uterine,  nasal  hemorrhage,  &c.  &c.  ; the  re- 
sult only  differs.  Now  in  this  last  case,  no  one  ever  sup- 
posed that  there,  was  a repercussion  of  fluid.  The  sup- 
pression of  the  transpiration  is  a thing  purely  accessory 


DERMOID  SYSTEM. 


329 


and  foreign  to  the  internal  inflammation  which  takes 
i)lace.  When  the  skin  sweats  in  summer,  the  vital  forces 
are  more  raised  by  the  caloric  which  penetrates  it ; in 
this  state,  it  is  more  capable  of  acting  s}^mpathetically 
upon  the  forces  of  the  other  systems.  Hence  why  all 
strong  stimulants  that  act  upon  it  are  more  to  he  feared 
then.  It  is  so  true  that  it  is  not  the  suppression  of  the 
sweat  which  is  dangerous,  but  the  alteration  of  the  vital 
forces  of  the  skin  which  sweats,  that  many  kinds,  as  the 
sweat  of  phthisis,  are  not  so  injurious  when  they  cease 
for  a time ; they  are  checked  even  with  much  more  diffi- 
culty, because  they  are  not  produced  by  a cause  acting 
immediately  upon  the  skin.  Now  if  there  was  a reper- 
cussion of  the  transpiration,  every  species  of  sweat  that 
was  suppressed  would  be  injurious.  We  never  hear  of  a 
peripneumony  arising  from  a suppression  of  sweat  pro- 
duced by  fear,  rheumatism,  &c.  There  would  be  then  also 
a repercussion  of  mucous  matter,  when  a pleurisy  arises 
from  swallowing  a glass  of  cold  water.  Men  judge  only 
by  that  which  is  striking.  The  suppression  of  the  sweat  is 
an  eflTect  like  inflammation  of  the  pleura,  but  it  is  not  the 
cause  of  it.  If  there  was  no  sweat  the  instant  the  cold 
was  applied  to  the  skin,  inflammmation  v/ould  neverthe- 
less come  on.  In  wounds  of  the  head,  with  abscesses  of 
the  liver,  &c.  there  is  no  repercussion  of  fluids. 

The  trembling  of  which  the  voluntary  muscles  become 
the  seat,  the  debility  of  the  pulse  which  the  weakness  of 
the  action  of  the  heart  produces,  &c.  are  phenomena  which 
the  influence  of  the  skin  affected  by  cold  alone  causes. 
In  fact,  only  this  organ,  the  commencement  of  the  mu- 
cous surfaces  and  all  of  that  of  the  bronchia,  are  made 
cold  by  the  external  air ; all  the  others  remain  at  their 
usual  temperature. 

We  know  the  innumerable  phenomena  wdiich  arise  from 
the  disappearance  of  herpes,  the  itch,  &c.  imprudently 
produced  ; in  all  these  cases  it  does  not  appear  that  the 
VOL.  III.  42 


330 


DERMOID  SYSTEM. 


morbific  matter  is  carried  to  the  other  organs,  though  I' 
do  not  pretend  that  this  never  happens.  It  is  the  vital 
forces  of  these  which  are  raised  and  which  then  occasion 
different  accidents  ; now  as  these  forces  vary  in  each  sys- 
tem, these  accidents  will  be  essentially  different ; thus  the 
same  morbific  cause  disappearing  from  the  skin,  will  pro- 
duce vomiting  if  thrown  upon  the  stomach,  in  which  the 
sensible  organic  contractility  predominates ; pains,  if  it 
goes  to  the  nerves  which  are  especially  characterized  by 
animal  sensibility  ; derangements  of  sight,  hearing  and 
smell,  if  it  affects  the  respective  viscera  of  these  senses ; 
hemorrhage,  catarrhs,  phthisis,  tubercular  inflammation, 
&c.  if  it  attacks  the  mucous  surfaces,  the  lungs,  the  serous 
membranes,  &c.  in  which  the  organic  sensibility  is  much 
raised.  Now,  if  the  same  morbific  matter  carried  upon 
these  different  organs,  produced  these  accidents,  they 
ought  to  be  uniform.  Do  not  their  varieties,  and  espe- 
ciall}'  the  constant  analogy  which  they  have  with  the  pre- 
dominant vital  forces  of  the  organs  in  which  they  appear, 
prove,  that  they  depend  upon  the  cause  which  I have 
pointed  out  ? 

We  know  that  the  serous  surfaces  and  the  cellular  tex- 
ture on  the  one  part,  and  the  skin  on  the  other,  are  often 
in  opposition  in  diseases.  There  is  no  sweat  when  drop- 
sies are  formed  ; the  dryness  of  the  skin  is  often  even 
more  remarkable  than  the  small  quantity  of  urine,  &c. 

3d.  When  the  cellular  texture  contained  in  the  dermoid 
spaces  is  inflamed,  as  in  phlegmonous  inflammation,  in 
biles,  in  some  malignant  pustules,  &c.  there  comes  on 
many  sympathies  which  can  be  referred  to  those  of  the 
general  cellular  system,  which  have  been  already  noticed. 

4th.  The  affections  of  the  chorion  itself,  all  mark- 
ed with  a chronic  character,  on  account  of  the  kind  of 
vitality  and  structure  of  this  portion  of  the  skin,  occasion 
also  sympathies  which  have  the  same  chronic  character, 
but  of  which  we  know  but  little. 


DERMOID  SYSTEM. 


331 


The  organic  contractility  cannot  be  put  sympatheticalr 
iy  in  action  in  the  skin,  as  it  does  not  exist  there. 

Characters  of  the  Vital  Properties.  First  Character. 

The  Cutaneous  Life  varies  in  each  organ. 

Though  we  have  spoken  in  general  of  the  vital  proper- 
ties of  the  skin,  they  are  far  from  being  uniform  or  at  the 
same  degree  in  all  the  regions. 

1st.  There  is  no  doubt  that  the  animal  sensibility  of  the 
soles  of  the  feet  and  the  palms  of  the  hands  is  greater 
than  that  of  the  other  parts.  Many  persons  are  so  sen- 
sible in  the  hypochondriac  region,  that  the  least  tickling 
there  produces  convulsions.  The  anterior  and  lateral  part 
of  the  trunk  is  always  more  sensible  than  the  region  of 
the  back. 

2d.  The  organic  properties  do  not  vary  less.  The  ex- 
treme susceptibility  of  the  face  to  receive  the  blood,  is  a 
proof  of  it,  as  I have  said.  It  is  generally  known  that 
some  parts  are  more  proper  than  others  for  the  applica- 
tion of  blisters.  Observe  on  this  subject  that  the  places 
where  the  animal  sensibility  predominates,  are  not  the 
same  as  those  in  which  the  organic  is  in  the  greatest  pro- 
portion. The  soles  of  the  feet  and  the  palms  of  the  hands 
hold  the  first  rank  in  relation  to  one,  and  the  face  in  re- 
lation to  the  other. 

In  diseases  we  also  see  these  varieties.  Who  does  not 
know  that  some  particular  parts  of  the  skin  are  especially 
the  seat  of  some  particular  cutaneous  affections,  and  that 
when  these  affections  are  general,  they  always  predomi- 
nate in  certain  places.  We  ought  not  to  be  astonished  at 
these  varieties,  since  we  have  seen  that  the  dermoid  tex- 
ture is  infinitely  variable  as  it  respects  its  papillse,  its  retic- 
ular body,  its  chorion,  &c. 


332 


DERMOID  SYSTEM. 


Second  Ckaracier.  Intermission  in  one  relation  : 
continuity  in  another. 

The  life  of  the  cutaneous  system  is  essentially  inter- 
mittent in  relation  to  animal  sensibility.  All  the  senses 
exhibit  this  plienomenon.  Thus  when  the  eye  has  for  a 
long  time  gazed  upon  objects,  the  ear  heard  sounds,  the 
nose  received  odours,  and  the  mouth  tastes,  these  dif- 
ferent organs  become  unfit,  to  receive  new  sensations  ; 
they  become  fatigued,  and  require  rest  to  regain  their 
forces.  It  is  the  same  with  regard  to  feeling  and  the 
touch  ; wearied  by  the  impression  of  surrounding  bodies, 
the  skin  requires  an  intermission  of  action  to  regain  ex- 
citability adapted  to  new  impressions.  We  know  that  a 
short  time  before  sleep,  external  bodies  produce  but  an 
obscure  sensation  upon  it,  and  that  their  contact  has  no 
effect  in  this  state,  in  which  animals  seem  to  lose  half  of 
their  existence.  The  more  powerfully  the  cutaneous 
sensibility  has  been  excited,  the  more  profound  is  sleep  ; 
hence  why  all  painful  exercises,  great  frictions,  &c.  are 
always  followed  by  a deep  sleep.  Yet  this  sense  can 
sometimes  exert  itself,  while  the  others  sleep  ; pinch  the 
leg  of  a man  asleep  ; he  draws  it  away  \vithout  waking, 
and  has  afterwards  no  remembrance  of  the  sensation. 
Thus  somnambulists  often  hear  sounds,  even  eat,  &c.  j 
for,  as  I have  said  elsewhere,  sleep  may  affect  but  a very 
limited  part  of  animal  life,  as  it  may  the  whole. 

Under  the  relation  of  organic  sensibility,  the  life  of  the 
cutaneous  system  is  essentially  continuous.  Thus  the 
functions  over  which  tliis  property  presides  have  a charac- 
ter opposite  to  tlie  preceding.  The  insensible  transpi- 
ration takes  place  continually,  though  there  may  be  some 
periods  in  which  it  is  more  active  than  in  others.  The 
oily  fluid  is  incessantly  carried  away  and  renewed  ; we 
might  even  saj)"  sometimes  that  it  is  when  the  animal 


DERMOID  SYSTEM. 


333 


sensibility  is  interrupted,  that  the  organic  is  in  the  great- 
est exercise. 

It  is  especially  in  diseases  that  they  have  made  this 
observation,  which  is  besides  genei’ally  applicable  to  or- 
ganic life.  All  this  life  is  as  active  and  even  more  so 
during  the  night  than  dui'ing  the  day.  Most  of  the  dis- 
eases that  attack  the  functions  which  belong  to  it,  are 
marked  by  an  increase  of  activity  during  the  night.  All 
fevers  which  particularly  affect  the  circulation  have  their 
exacerbation  towards  night.  In  diseases  of  the  heart,  the 
patients  are  more  oppressed  at  this  period,  &c.  In  phthisis 
which  affects  respiration,  it  is  in  the  night  especially  that 
there  is  hectic  fever,  sweats,  &c.  Pneumonia  and  pleu- 
risy, exhibit  frequent  exacerbations  towards  night.  In 
glandular  diseases,  either  acute  or  chronic  we  make  the 
same  observation.  It  would  be  necessary  to  refer  to 
almost  all  the  affections  which  alter  especially  an  organic 
function,  in  order  to  omit  nothing  upon  this  point.  On 
the  contrary,  observe  hemiplegia,  epilepsy,  convulsions, 
various  paralysies  of  the  different  organs  of  sense,  most 
mental  alienations,  apoplexy  and  other  affections  which 
exert  their  influence  more  particularly  upon  animal  life, 
they  have  not,  so  often  at  least,  their  exacerbations  to- 
wards evening  and  during  the  night,  no  doubt  because- in 
the  natural  state,  this  life  is  in  the  habit  of  becoming 
drowsy  and  not  of  being  raised  like  the  other  which  seems 
to  imprint  this  character  upon  its  alterations.  Other 
causes  no  doubt  have  an  influence  upon  this  phenomenon  ; 
but  I believe  this  to  be  a real  one. 

Third  Character.  Influence  of  the  Sexes. 

The  sex  has  an  influence  upon  the  cutaneous  life.  In 
general  the  animal  portion  of  this  life  is  more  raised  in 
women,  in  whom  every  thing  that  belongs  to  the  sensa- 
tions is  proportionally  more  marked  than  in  man,  who  pre- 
dominates by  the  power  of  his  locomotive  muscles.  The 


534 


DERMOID  SYSTEM. 


.effects  of  tickling  are  infinitely  more  powerful  in  females. 
All  the  arts  which  require  nicety  and  delicacy  of  touch  are 
advantageously  cultivated  by  women.  The  peculiar  tex- 
ture of  the  chorion,  a texture  generally  more  delicate,  has 
no  doubt  an  influence  upon  this  phenoinenon.  As  to  the 
organic  portion  of  the  cutaneous  life,  the  difference  is 
not  very  great.  Man  appears  to  be  superior  in  this  re- 
spect ; he  generally  sweats  more  ; his  skin  is  more  unctu- 
ous, which  proves  a greater  secretion. 

Fourth  Character.  Influence  of  Temperament. 

The  temperament  peculiar  to  each  individual  is  not  a 
less  real  cause  of  differences  in  the  skin.  We  know  that 
the  colour,  roughness  and  pliability  of  this  organ  vary 
according  as  individuals  are  sanguineous,  phlegmatic,  &c. 
that  these  external  attributes  are  even  a character  of  the 
temperaments.  Varieties  of  structure  no  doubt  coincide 
with  these.  Is  it  then  astonishing  that  the  animal  sensi- 
bility differs  so  much,  that  the  touch  itself  should  be  deli- 
cate in  some  and  dull  in  others,  that  some  should  be  very 
ticklish,  whilst  others  are  not  so  at  all,  &c.  ? Ought  we 
to  be  astonished  if  the  organic  sensibility,  which  is  very 
variable,  should  determine,  according  to  the  individuals, 
many  varieties  in  the  phenomena  over  which  it  presides  ; 
if  in  some,  it  allows  much  blood  to  go  to  the  face,  and 
if  it  repels  this  fluid  in  others  who  are  always  pale  ; if 
some  men  sweat  much,  whilst  others  have  the  skin  almost 
always  dry  ; if  the  cutaneous  oil  varies  in  quantity ; if 
there  are  some  skins  much  disposed  to  eruptions,  either 
acute  or  chronic,  to  pimples  of  different  natures,  and  if 
others  are  almost  always  free  from  them,  even  when  the 
individuals  expose  themselves  to  the  contagion  of  these 
diseases ; if  superficial  wounds,  of  the  same  extent  and 
made  by  the  same  instrument,  are  sometimes  quicker  and 
.sometimes  slower  in  healing ; if  the  cure  of  cutaneous 
diseases  is  also  ver}'  variable  in  its  periods,  &c.  &c.  ? 


DERMOID  SYSTEM. 


333 


ARTICLE  FOURTH. 


DEVELOPMENT  OF  THE  DERMOID  SYSTEM. 


I.  S'^a^e  of  this  System  in  the  Fcetns. 


In  the  first  periods  after  conception,  the  skin  is  but 
a kind  of  glutinous  covering,  which  seems  to  be  gradually 
condensed,  forms  a transparent  envelope,  through  which 
we  see  in  part  the  subjacent  organs,  the  vessels  especially, 
and  which  is  torn  by  the  least  jar.  This  state  continues 
for  a month  and  a half  or  two  months.  The  consistence 
constantly  increasing,  soon  gives  to  the  skin  an  appear- 
ance more  nearly  like  that  which  it  has  in  infants  after 
birth.  Its  delicacy  is  extreme  at  this  period.  It  has  not 
one  quarter  the  thickness  of  that  of  the  adult.  The  mo- 
ment in  which  it  begins  to  lose  its  mucous  state  appears 
to  be  that  in  which  the  fibres  of  the  chorion  are  formed. 
Until  then  the  cellular  texture  and  the  vessels  especially 
composed  it,  and  as  the  first  is  abundantly  filled  with 
juices  during  the  early  periods,  it  is  not  astonishing  that  it 
should  then  give  way  under  the  least  pressure.  But  when 
the  fibres  are  formed,  the  cellular  texture  diminishes  on 
the  one  hand,  and  is  concentrated  in  the  spaces  that  are 
developed,  and  on  the  other  the  dermoid  fibres,  more  dense 
than  its  layers,  increase  the  resistance. 

W e do  not  see  upon  the  external  surface  of  the  skin  of 
the  foetus  most  of  the  wrinkles  of  which  we  have  spoken 
above.  Those  of  the  face  in  particular  are  not  seen  ; the 
kind  of  immobility,  in  which  the  facial  muscles  are,  is 
evidently  the  reason  of  it.  The  forehead,  the  eyelids, 


DEIIMOID  SYSTEM. 


33() 

the  edges  of  the  lips,  Sac.  are  smooth.  Besides,  the 
abundance  of  fat  which  then  distends  the  integuments  of 
the  cheeks,  prevents  every  species  of  fold  there.  As  the 
hands  and  the  feet  are  found  in  part  bent  at  their  articula- 
tions, by  the  attitude  of  the  foetus,  different  wrinkles  are 
already  formed  about  these  articulations,  principally  on 
the  hand,  where  however  they  appear  less  in  proportion 
than  afterwards.  The  curved,  papillary  lines  are  not  very 
evident  on  the  foot  and  the  hand,  even  when  the  epider- 
mis is  removed. 

The  internal  surface  of  the  skin  is  remarkable  for  the 
.slight  adhesion  of  the  subjacent  cellular  texture,  the  cells 
of  which  filled  with  fatty  particles  are  removed  with  great 
ease,  by  scraping  this  surface  w’ith  the  edge  of  a knife. 
We  see  then  there  the  spaces  already  well  formed,  and  as 
distinct  in  proportion  as  afterwards.  By  pursuing  their 
dissection  from  within  outwards,  we  insensibly  lose  sight 
of  them  towards  the  external  surface  where  the  skin  is 
condensed. 

More  blood  enters  the  skin  of  the  foetus,  than  at  any 
other  period  of  life.  It  is  easy  to  observe  this  in  small 
animals  taken  alive  from  the  womb  of  their  motlier;  for 
in  the  fetuses  that  are  dead  at  birth,  or  born  prematurely, 
the  cause  which  destroys  life,  increasing  or  diminishing 
in  the  last  moments  the  quantity  of  cutaneous  blood,  pre- 
vents us  from  drawing  any  conclusion  as  to  the  ordinary 
state  by  an  inspection  of  them.  The  nerves  are,  as  in  all 
the  other  parts,  more  evident ; but  the  papillae,  though  sen- 
sible, as  I have  said,  have  not  a propcrlionable  increase. 

The  animal  sensibility  is  not  in  exercise  in  the  skin  of 
the  fetus,  or  at  least  it  is  very  obscure  there.  This  is 
owing  to  the  absence  of  the  causes  of  excitement.  These 
are  the  surrounding  heat,  the  waters  of  the  amnios  and 
the  parietes  of  the  womb,  which  can  furnish  materials  for 
sensations  ; but  as  these  causes  are  always  uniform,  and 
have  no  varieties,  the  fetus  can  have  but  a very  feeble 


DERMOID  SYSTEM. 


33T 


perception,  because  acuteness  of  sensation  requires  change 
of  stimuli.  We  know  that  heat  long  continued  at  the 
same  degree  becomes  insensible,  that  a long  continuance 
in  a bath  takes  away  almost  entirely  the  sensation  of  the 
water,  because  habit  is  every  thing  as  it  respects  sensa- 
tion ; nothing  but  what  is  new  affects  us  powerfully. 

Is  the  organic  sensibility  of  the  skin  in  activity  in  the 
fcetus  ? does  it  preside  over  the  alternate  exhalation  and 
absorption  of  the  waters  of  the  amnios  ? This  is  not  the 
common  opinion,  it  is  not  even  a probable  one  ; but  this 
question  is  far  from  being  settled  in  so  precise  a manner 
as  many  other  points  of  physiology. 

Besides,  it  cannot  be  doubted  that  there  is  a copious 
secretion  of  an  unctuous  and  viscid  fluid,  which  covers 
the  whole  body  of  the  foetus,  but  which  is  more  abundant 
in  some  places  than  others,  as  behind  the  ears,  in  the 
groin,  the  axilla,  &c.  either  because  it  is  secreted  there 
in  greater  quantity,  or  accumulated  on  account  of  the 
arrangement  of  the  parts.  Accoucheurs  have  it  wiped  off 
after  birth,  and  the  females  of  animals  remove  it  by  the 
repeated  application  of  their  tongues  to  the  surface  of  the 
body.  This  fluid  appears  to  be  to  the  skin  of  the  foetus 
what  the  oily  fluid  is  to  that  of  the  adult ; it  defends  this 
organ  from  the  impression  of  the  waters  of  the  amnios. 
If  the  sebaceous  glands  exist,  it  would  appear  that  they 
furnish  it,  for  it  is  certainly  from  a different  source  from 
the  sweat.  When  care  has  not  been  taken  to  remove  this 
covering,  it  irritates  the  skin,  and  may  produce  excoria- 
tions, and  a species  of  erysipelas.  The  air  cannot  remove 
it  by  solution.  Nothing  similar  oozes  from  the  skin  of 
the  infant  after  birth.  Is  it  because  the  black  blood  alone 
is  capable  of  furnishing  the  materials  of  this  substance  } 

II.  State  of  the  Dermoid  System  during  growth. 

At  the  moment  of  birth  the  dermis  experiences  a sud- 
den revolution.  Hitherto  entered  only  by  black  blood, 
voL.  III.  43 


338 


DERMOID  SYSTEM. 


it  is  at  the  time  the  fetus  is  born,  more  or  less  coloured 
by  it.  Some  fetuses  come  wholly  livid,  others  are  paler ; 
there  is  a remarkable  variety  in  this  respect.  But  all, 
shortly  after  they  have  respired,  become  more  or  less  de- 
cidedly red.  It  is  owing  to  the  arterial  blood  which  is 
formed  and  succeeds  the  venous  blood  that  circulated  in 
the  cutaneous  arteries.  In  this  respect  the  state  of  the 
skin  is  in  general  an  index  of  what  goes  on  in  the  lungs. 
If  an  infant  remains  a long  time  of  a violet  colour,  he 
either  does  not  breathe  or  breathes  with  difficulty.  The 
extremities  of  the  hands  and  the  feet  in  general  become 
red  the  last.  They  are  those  in  which  the  lividity  con- 
sequently continues  the  longest,  when  this  lividity  is  very 
evident.  The  blood  which  goes  to  the  cutaneous  organ, 
enters  it  in  general  in  a very  uniform  manner ; the  cheeks 
do  not  appear  to  receive  more  of  it  in  proportion.  The 
sudden  excitement  it  brings  to  the  organ,  raises  its  vital 
forces  and  renders  it  more  fit  to  receive  the  impressions, 
which  are  new  to  it,  of  the  surrounding  bodies. 

Observe  in  fact  that  a thousand  different  agents,  the 
surrounding  temperature,  the  air,  dress,  the  fluid  in  which 
the  fetus  is  washed,  the  tongues  of  those  quadrupeds  who 
lick  their  young,  carry  to  the  skin  an  excitement  which 
is  so  much  the  more  felt  by  the  fetus,  as  it  is  not  accus- 
tomed to  it,  and  as  there  is  an  essential  difference  be- 
tween these  stimuli,  and  those  to  which  it  had  been  pre- 
viously subjected.  It  is  then  that  the  remarkable  sympa- 
thy which  connects  the  skin  with  all  the  other  organs, 
becomes  especially  necessary.  Every  thing  within  soon 
perceives  the  new  excitements  that  are  applied  without. 
It  is  these  excitements,  those  of  the  mucous  surfaces  at 
tlieir  origin  and  those  of  the  whole  of  the  bronchia,  which 
especially  bring  into  action  many  organs  hitherto  inactive. 
There  happens  then,  what  is  observed  in  syncope,  in  which 
respiration,  circulation,  the  cerebral  action  and  many  func- 
tions suspended  by  the  affection,  are  suddenly  roused  up 


DERMOID  SYSTEM. 


339 


by  external  friction,  by  the  irritation  of  the  pituitary 
membrane,  &c.  The  phenomena  are  different,  but  the 
principles  from  which  they  are  derived  in  both  cases  are 
the  same. 

Then  the  organic  sensibility  is  also  raised.  Transpi- 
ration is  established.  The  skin  begins  to  be  an  emunctory 
of  different  substances,  which  it  did  not  before  throw 
out ; it  becomes  also  capable  of  absorbing  different  prin- 
ciples applied  to  its  surface.  The  skin  of  the  foetus  is 
hardly  ever  the  seat  of  any  kind  of  eruptions  ; then  pim- 
ples of  different  kinds  frequently  appear. 

All  the  parts  of  the  cutaneous  organ  do  not  however 
appear  to  be  raised  to  the  same  degree  of  organic  sensi- 
bility. For  a long  time  after  birth  the  skin  of  the  crani- 
um appears  to  be  the  centre  of  a more  active  life ; it  be- 
comes the  frequent  seat  of  many  eruptions,  all  of  which 
denote  an  excess  of  the  vital  forces.  The  different  kinds 
of  scurf  with  which  it  is  covered  do  not  appear  elsewhere. 
In  this  respect,  the  skin  of  the  cranium  follows,  like  the 
bones  of  this  part  and  the  cerebral  membranes,  the  early 
development  of  the  brain,  which,  on  this  account  is  the 
seat  of  diseases  in  infancy  more  than  at  any  other  age. 

The  skin  of  the . face  seems  to  be  sometimes  in  less 
activity.  In  the  first  months  after  birth,  it  has  not  that 
bright  colour  which  it  will  afterwards  have  upon  the 
cheeks,  and  which  does  not  commence  until  the  develop- 
ment of  the  sinuses  and  dentition  bring  to  this  part  more 
vital  activity  for  the  nutritive  work.  It  is  also  towards 
this  period  that  the  eruptions  of  which  this  part  of  the 
cutaneous  system  is  especially  the  seat,  like  those  of  the 
small-pox,  measles,  &c.  begin  to  take  place. 

For  a long  time  after  birth  the  skin  still  preserves  a 
remarkable  degree  of  softness ; a very  great  quantity  of 
gelatine  enters  it ; this  substance  is  obtained  from  it  with 
great  ease  by  ebullition,  which,  continued  for  some  time, 
finally  melts  this  organ  entirely.  The  fibrous  part  noticed 


340 


DERMOID  SYSTEM, 


by  Seguin,  is  in  very  small  quantity.  I think  it  is  this 
predominance  of  tlie  gelatinous  portion  of  the  skin,  which 
renders  that  of  young  animals  easy  of  digestion.  We 
know  that  in  calves’  heads,  roasted  lamb,  and  small  suck- 
ing pigs,  prepared  for  our  tables,  it  presents  an  aliment 
which  the  digestive  juices  alter  with  the  greatest  ease  ; 
whilst  that  of  animals  of  mature  age  and  especially  old 
ones,  cannot  be  digested  by  them.  The  carnivorous 
species  tear  their  prey,  feed  upon  its  internal  organs,  the 
muscles  especially,  and  leave  the  skin.  Now  what  is  it 
that  makes  the  skin  of  young  animals  differ  from  that  of 
old  ones  ? It  is  because  the  gelatinous  substance  predomi- 
nates over  the  fibrous  in  the  first,  and  the  fibrous  pre- 
dominates in  the  second. 

The  skin  of  children  is  gradually  thickened  ; but  it  is 
not  until  the  thirtieth  year  that  it  acquires  the  thickness 
that  it  is  always  to  have  afterwards.  Till  then  the  dif- 
ferent ages  are  marked  in  this  respect  by  different  degrees. 
Take  a portion  of  skin  at  birth,  at  two,  six,  ten,  fifteen, 
twenty  years,  &c.  you  will  see  these  differences  in  a re- 
markable manner.  The  more  its  thickness  increases  the 
more  compact  it  becomes  ; it  is  because  the  fibrous  sub- 
stance tends  constantly  to  predominate  over  the  gela- 
tinous. 

As  we  advance  in^age,  the  adhesion  of  the  internal  sur- 
face of  the  dermis  with  the  subjacent  cellular  texture  be- 
comes much  greater.  It  is  more  difficult  to  detach  one 
from  the  other.  On  the  external  surface  the  wrinkles  of 
the  face  are  gradually  formed.  Smiles  and  tears  agitate 
the  face  of  the  infant  the  most.  One  is  the  expression  of 
the  happiness,  the  other  of  the  uneasiness  which  all  its 
passions  produce  in  its  mind.  Now  the  wrinkles  which 
weeping  occasions  on  the  eyelids  are  marked  in  rather  a 
more  permanent  manner,  either  because  weeping  is  more 
frequent  than  smiling,  or  because  continual  winking  adds  to 
the  motion  which  weeping  produces,  or  because  less  fat  is 


DERMOID  SYSTEM. 


341 


found  in  this  place.  As  smiling  is  on  the  one  hand  more 
rare,  and  on  the  other  much  fat  puffs  out  the  cheeks  of 
the  infant,  the  perpendicular  wrinkles  formed  by  the 
muscles  of  the  face,  which  in  this  motion  separate  trans- 
versely the  features  from  within  outwards,  are  much 
slower  in  forming.  Besides,  the  nursing  of  the  infant, 
which  requires  the  contraction  of  its  face  from  without 
inwards,  opposes  their  formation.  The  wrinkles  of  the 
forehead  are  always  very  slow  in  forming,  because  the 
motions  which  contract  the  eyebrow,  and  those  which 
wrinkle  the  forehead,  are  rare  in  the  infant,  who  has 
hardly  any  of  those  dark  passions  which  these  motions 
serve  to  depict. 

The  growth  of  the  dermoid  system  has  not  remarkable 
revolutions  like  that  of  most  of  the  others ; it  goes  on  in 
an  uniform  manner.  At  the  period  of  the  growth  of  the 
hairs,  it  does  not  change,  because  this  growth  is  abso- 
lutely foreign  to  it,  these  productions  only  passing  through 
it.  At  puberty  it  increases  in  energy  like  all  the  other  sys- 
tems. Until  then  sweats  had  not  been  very  copious  ; for, 
other  things  being  equal,  we  may  say  that  children  sweat 
less  in  general  than  adults,  and  that  the  residue  of  their 
nutrition  passes  rather  by  the  urine,  which  is  probably  the 
reason  why  they  are  so  remarkably  disposed  to  calculi. 
Beyond  the  twentieth  year  we  begin  to  sweat  more,  and 
until  old  age,  especially  in  summer,  the  fluids  appear  to 
go  out  in  this  way. 

III.  State  of  the  Dermoid  System  after  Growth. 

After  growth,  the  skin  continues  for  a long  time  to 
have  great  activity  ; the  excess  of  life  which  animates  it, 
renders  it  capable  of  influencing  with  ease  the  other  or- 
gans if  it  be  but  a little  excited.  Hence  the  disposition  to 
pneumonia,  pleurisy,  &c.  from  the  action  of  cold  on  the 
skin  in  sweat,  a state  in  which  it  is  more  disposed  to  exert 
an  injurious  influence  upon  the  internal  organs,  because 


342 


DERMOID  SI  STEM. 


its  forces  are  more  excited.  As  to  the  different  affections 
which  result  from  tliis  influence,  they  depend  upon  the 
internal  organs  upon  which  it  is  directed  ; so  that  the 
same  sympathetic  irradiations  going  from  the  skin,  will 
produce  sometimes  an  affection  of  the  abdomen,  some- 
times a disease  of  the  thorax,  according  to  the  age  in 
which  the  abdominal  or  pectoral  organs,  predominating 
by  their  vitality,  are  more  disposed  to  answer  to  the  in- 
fluence directed  in  general  upon  the  whole  economy. 

The  skin  becomes  more  and  more  firm  and  resisting 
as  we  advance  in  age,  as  the  fibrous  substance  is  constantly 
tending  to  a predominance  over  the  gelatinous.  Less 
blood  seems  to  be  carried  to  it.  It  becomes  less  and  less 
disposed  to  eruptions,  so  cominon  in  youth  and  infancy, 
&.C.  I will  not  speak  of  its  other  differences  ; for  all  that 
we  have  said  of  it  in  the  preceding  articles  relates  espe- 
cially to  the  adult  age. 

I will  only  observe  that  if,  during  the  greatest  part  of 
life,  the  skin  be  so  fruitful  a source  of  diseases,  and  the 
various  alterations  it  experiences  produce  so  frequent  dis- 
orders in  the  internal  organs,  it  is  only  owing  to  the 
varied  causes  of  excitement  to  which  it  is  every  instant 
subjected.  If  the  glands,  the  serous  surfaces,  &c.  have 
an  influence  less  frequently  upon  the  other  organs,  it  is 
because  being  deeply  situated,  and  almost  always  in  con- 
tact with  the  same  excitants,  they  are  not  subject  to  so 
many  revolutions  in  their  vital  forces.  The  secreted  fluids 
and  those  exhaled  in  the  serous  and  synovial  systems  are 
not,  for  the  same  reason,  so  much  subject  to  those  con- 
siderable increases,  and  those  sudden  suppressions  which 
so  frequently  happen  to  the  sweat. 

Observe  that  society  has  also  multiplied  to  a great  ex- 
tent the  injurious  excitements  to  which  the  skin  is  sub- 
jected. These  excitements  consist  especially  in  the  rapid 
passage  from  heat  to  cold,  whicli  makes  the  latter  act 
very  powerfully  upon  the  cutaneous  sensibility,  which 


DERMOID  SYSTEM. 


343 


like  that  of  all  the  other  systems,  answers  so  m.uch  the 
more  to  excitements  made  upon  it,  as  they  are  different 
from  those,  whose  action  they  had  previously  experienced. 
In  the  natural  state,  there  is  only  the  succession  of  the 
seasons  ; nature  knows  how  to  connect  insensibly  heat 
with  cold,  and  to  make  the  transition  but  rarely  abrupt. 
But  in  society,  the  different  garments,  the  artificial  de- 
grees of  temperature  of  our  apartments,  degrees  differing 
at  first  from  that  of  the  atmosphere,  then  varying  greatly 
from  each  other,  so  that  the  same  man  who  in  winter  en- 
ters thirty  apartments,  is  often  subjected  to  thirty  different 
temperatures  ; the  hard  labour  in  which  most  men  are  en- 
gaged, and  which  makes  them  sweat  copiously,  every 
thing  incessantly  presents  numerous  causes  which  make 
the  vital  forces  of  the  dermoid  system  vary  rapidly.  Thus 
the  bronchial  mucous  surface  is  constantly  in  contact  in 
cities,  with  a thousand  excitements  that  are  continually 
renewed,  and  with  which  the  air  is  not  charged  in  a 
natural  state.  Thus  the  alimentary  substances,  continu- 
ally varying  in  their  composition,  temperature,  &c.  change 
the  excitement  of  the  gastric  mucous  surface,  and  are  the 
source  of  many  affections,  from  which  most  animals  ai’e 
exempt  by  the  uniformity  of  their  food. 

If  the  skin  and  the  mucous  surfaces  were  always  kept 
at  the  same  degree  of  excitement  by  the  constant  unifor- 
mity of  the  stimuli,  they  would  certainly  be  a much  less 
fruitful  source  of  diseases,  as  is  clearly  proved  by  the 
foetus,  which  is  hardly  ever  sick,  because  all  the  external 
causes  which  act  upon  its  mucous  and  cutaneous  sensibi- 
lity, as  the  heat,  the  waters  of  the  amnios  and  the  parietes 
of  the  womb,  do  not  vary  until  birth.  At  this  period, 
animals  brought  into  a new  medium,  find  many  more 
varieties  in  the  stimuli  which  act  upon  them,  even  in  a 
natural  state  and  far  from  society  ; thus  their  diseases  are 
naturally  much  more  frequent  after  than  before  birth.  In 
society,  in  which  man  has  increased  four,  six  and  even 


DERMOID  SYSTEM. 


‘J44 

ten  times  the  number  of  the  stimuli  which  affect  the  sur- 
faces destined  to  be  in  contact  with  the  external  bodies,  is 
it  astonishing  that  the  diseases  should  be  so  dispropor- 
tioned  to  those  of  animals  ? 


IV.  State  of  the  Dermoid  System  in  Old  nB.ge. 

Towards  the  decline  of  life,  the  dermoid  system  be- 
comes more  and  more  firm  and  compact ; it  is  softened 
with  great  difficulty  by  ebullition.  The  gelatine,  which 
it  yields,  is  less  abundant  and  more  hard  and  consistent. 
I think  it  would  not  be  fit  to  make  any  kind  of  glue, 
even  the  strongest,  unless  mixed  with  that  of  adult  ani- 
mals. Its  yellowish  tinge  becomes  very  deep.  When  it 
is  cooled,  it  requires  a much  stronger  and  more  durable 
fire  to  melt  it ; the  fibrous  portion  of  the  dermis  which 
does  not  melt  or  at  least  resists  for  a long  time,  is  in- 
finitely greater  in  proportion.  It  is  like  the  bones  in 
which  the  gelatinous  portion  is  in  an  inverse  ratio,  and 
the  earthy  portion  in  a direct  ratio  to  the  age. 

The  dermoid  texture  becomes  then  like  all  the  others, 
dense  and  stiff;  it  is  not  proper  for  our  food,  the  teeth 
cannot  tear  it.  Prepared  with  tannin,  it  is  more  resisting 
and  less  pliable,  and  cannot  on  that  account  serve  for  the 
same  purposes  as  that  taken  from  young  animals.  Every 
one  knows  the  difference  of  the  leather  of  calves  and  oxen, 
especially  when  the  latter  are  old.  This  difference  is 
owing  first  to  the  thickness,  which  being  much  greater  in 
the  second  than  the  first,  does  not  allow  it  to  be  so  easily 
bent  in  different  directions  ; and  then  to  the  nature  of  the 
texture  itself.  Cut  in  two  horizontally  a piece  of  the 
leather  of  an  ox  ; each  half  will  be  as  thin  as  a piece  of 
calves  skin,  and  yet  it  will  be  less  pliable.  I do  not  esti- 
mate here  the  varieties  which  may  depend  on  the  greater 
or  less  quantity  of  tannin  that  may  be  combined  with  it ; 
I suppose  the  proportions  to  be  all  equal. 


DERMOID  SYSTEM. 


345 


Submitted  to  dessiccation,  the  human  dermoid  texture 
becomes  much  more  stiff  in  old  age  than  in  the  preceding 
ones.  Maceration  softens  it  with  more  difficulty.  The 
hair  of  a child  falls  out  much  sooner  by  it  than  that  of 
an  old  person  ; thus  it  requires  longer  to  clean  the  skins 
of  old  animals  than  those  of  young  ones  tanners  know 
this  very  well.  I would  remark  upon  this  subject,  that 
the  skins  of  animals,  having  more  hairs  pass  through  them, 
exhibit  in  comparison  with  that  of  man,  an  innumerable 
quantity  of  little  pores  on  their  external  surface  ; which 
favours  in  them  on  this  surface  the  action  of  tannin,  which 
insinuating  itself  into  the  dermoid  spaces  and  filling  them 
completely  with  a new  substance  formed  by  the  combina- 
tion of  tannin  with  gelatine,  occupies  entirely  the  texture 
of  the  spaces.  The  previous  maceration  to  which  the 
skin  has  been  exposed,  favours  not  only  the  removal  of 
the  hairs,  but  facilitates  also  to  a great  degree  the  en- 
trance of  the  tannin,  by  separating  the  fibres  of  the  spaces, 
by  making  them  larger,  and  increasing  the  size  of  the  ex- 
ternal pores. 

The  more  we  advance  in  age,  the  less  is  the  quantity  of 
blood  that  penetrates  the  skin.  The  redness  of  the  cheeks 
disappears  in  old  people.  We  no  longer  see  then  the 
rosy  complexion  of  the  young  man  and  even  of  the  adult, 
and  which  arose  from  the  vessels  winding  through  the 
cellular  texture  of  the  spaces  of  the  chorion. 

The  continual  pressure  of  external  objects  increases 
then  remarkably  the  adhesion  of  the  subjacent  cellular 
texture  to  the  dermis.  They  are  separated  from  each  other 
with  great  difficulty  by  carrying  the  edge  of  a scalpel 
over  the  internal  face  of  the  chorion ; a circumstance 
which  is  owing  also  to  this,  that  the  cellular  texture  hav- 
ing become  more  dense,  is  less  easily  torn  ; for  this  tear- 
ing is  then  necessary,  considering  the  continuity  of  the 
sub-dermoid  layer  with  that  which  enters  the  spaces. 

VOL.  in.  44 


34G 


DERMOID  SYSTEJI. 


The  exterioi'  of  the  skin  is  uneven  and  rough.  All  the 
wrinkles  of  which  we  have  spoken  become  infinitely  more 
evident ; many  belong  exclusively  to  this  age. 

The  vital  forces  of  the  dermoid  system  are  more  weak- 
ened in  old  age  than  those  of  most  of  the  others,  because 
it  is  more  excited  during  life  by  external  bodies.  Most 
of  these  bodies  then  make  no  impression  upon  it.  The 
habit  of  feeling  has  blunted  the  animal  sensibility.  The 
touch  is  exercised  but  rarely  ; for,  as  I have  observed, 
this  sense  requires  to  put  it  in  action,  the  previous  exer- 
cise of  the  will.  We  touch,  because  we  have  previously 
seen,  heard,  tasted,  &c.  in  order  to  correct  or  confirm  our 
other  sensations ; now  the  old  man,  to  whom  every  thing 
around  is  known,  to  whom  nothing  is  new,  is  induced 
to  touch  nothing.  Compare  in  this  respect  the  two  ex- 
treme ages  of  life.  The  infant,  to  whom  every  thing  that 
strikes  his  eyes,  his  ears,  his  nostrils,  &c.  is  unknown, 
who  finds  in  every  thing  that  surrounds  him  new  objects 
of  sensation,  wishes  to  touch  and  lay  hold  of  every  thing. 
Its  little  hands  are  in  continual  agitation.  To  touch  is  a 
pleasure  to  him,  for  every  new  object  of  sensation  is 
agreeable.  If  in  his  last  years,  man  was  transported  into 
the  midst  of  objects  that  never  before  struck  his  senses, 
he  would  oftener  exercise  his  touch ; but  none  of  those 
things  excite  him  among  which  he  has  always  lived. 
Hence  why  old  age  is  not  the  age  of  enjoyments.  In 
fact  all  our  pleasures  are  almost  relative  ; we  have  but 
little  that  is  absolute  ; now  as  habit  blunts  all  the  relative 
pleasures,  which  cease  because  they  have  existed,  the 
more  the  sensations  are  accumulated  by  time,  the  less 
there  are  of  new  ones  left  to  be  experienced,  and  the  more 
are  the  sources  of  happiness  dried  up.  For  a contrary 
reason,  the  happiest  age  is  infancy,  because  it  has  before 
it  the  whole  field  of  sensations  to  go  over.  Man  at  every 
step  of  his  career  leaves  behind  him  a cause  of  his  en- 
joyments. When  arrived  at  the  end  he  finds  only  indif- 


DERMOID  SYSTEM. 


347 


ference,  a state  very  suitable  to  his  situation,  since  it 
diminishes  the  distance  that  separates  life  from  death. 

The  organic  sensibility  of  the  skin  is  not  less  blunted 
in  old  age,  than  its  animal  sensibility ; hence  the  follow- 
ing phenomena  ; 1st,  contagious  miasmata  are  absorbed 
with  difficulty  at  this  age  ; almost  all  pass  over  the  cuta- 
neous surface  with  impunity.  2d.  The  exhalation  of 
sweat  is  uniformly  less ; it  is  hardly  ever  subject  to  those 
great  increases,  that  are  seen  in  the  adult.  3d.  The  oily 
fluid  is  also  furnished  in  much  less  quantity ; hence  the 
constant  dryness  of  the  exterior  of  the  skin,  the  cracking 
of  the  epidermis  in  some  cases,  &c.  4th.  All  the  diseases 
which  suppose  an  increase  of  this  organic  sensibility  are 
much  more  rare.  Erysipelas  and  the  difierent  kinds  of 
eruptions  are  a proof  of  it.  When  these  affections  take 
place,  they  have  a character  of  remarkable  slowness.  5th. 
The  skin  resists  external  cold  much  less  ; it  loses  easily 
the  caloric  of  the  body,  which  always  tends  to  escape  in 
order  to  be  in  equilibrium  with  that  of  the  surrounding 
medium  ; thus  old  people  are  always  fond  of  heat.  6th. 
I am  well  persuaded  that  the  skin  would  resist  also  less, 
at  this  age,  a degree  of  temperature  greater  than  that  of 
the  body,  and  as  it  permits  the  internal  caloric  to  be  easily 
lost  in  a colder  medium,  it  would  allow  the  external  to 
penetrate  in  a warmer  one.  It  would  be  very  curious  to 
repeat,  on  the  two  extreme  ages  of  life,  the  experiments 
of  the  English  physicians. 


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EPIDERMOID  SYSTEM. 


IF  we  examine  attentively,  it  is  easy  to  perceive  the 
immense  difference  there  is  between  the  preceding  system 
and  this,  v/hich  physiologists  have  considered  as  one  of 
its  dependancies.  Organization,  properties,  composition, 
functions,  growth,  &c.  every  thing  differs  in  the  two.  By 
explaining  these,  the  line  of  demarcation  that  separates 
them  will  be  perceived. 

I rank  in  this  system,  1st,  the  external  epidermis  ; 2d, 
that  which  is  spread  upon  the  mucous  system,  or  at  least 
upon  one  of  its  parts  ; 3d,  the  nails.  Though  these  last 
differ  very  much  from  the  epidermis  in  their  external 
appearance,  yet  they  resemble  it  in  so  many  respects, 
that  it  is  difficult  not  to  place  them  in  the  same  system. 
In  fact  the  nails  serve  as  an  epidermis  for  the  skin  which 
is  subjacent  to  them  ; they  are  continued  with  that  of  the 
fingers  in  an  evident  manner,  are  detached  and  regener- 
ated during  life  with  the  same  phenomena.  The  compo- 
sition appears  to  be  very  analogous.  The  kind  of  ex- 
crescences is  the  same.  After  death,  the  nails  are  de- 
tached by  the  same  means  as  the  epidermis,  and  then 
make,  as  it  were,  a part  of  it. 


S50 


EPIDERMOID  SYSTEM, 


ARTICLE  FIRST. 

OP  THE  EXTERNAL  EPIDERMIS. 


The  external  epidermis  is  a transparent  membrane, 
more  or  less  thick,  according  to  the  regions  in  which  it 
is  examined,  covering  everywhere  the  skin,  and  receiving 
immediately  the  excitement  of  external  bodies  which 
would  act  too  powerfully  upon  this. 

I.  Foi'ms,  Relations  with  the  Dermis,  Sfc. 

We  see  upon  the  epidermis  the  same  wrinkles  as  upon 
the  skin,  because  being  exactly  contiguous,  both  wrinkle 
at  the  same  time.  Different  pores  open  on  its  surface 
after  having  passed  through  it.  Some  transmit  the  hairs ; 
these  are  the  most  apparent;  others  give  passage  to  the 
exhalants.  We  do  not  see  these  in  the  natural  state,  be- 
cause their  course  is  oblique,  and  they  open  between  two 
small  layers,  which,  being  in  contact  with  each  other 
when  we  do  not  sweat,  conceal  their  termination.  But 
if,  the  skin  being  very  dry,  we  suddenly  sweat,  as  after 
drinking  tea,  then  the  little  drops  which  escape  from  the 
whole  cutaneous  surface,  not  having  had  time  to  run 
together,  but  remaining  separate,  we  see,  by  the  places 
where  they  are,  the  orifice  of  the  exhalants.  Besides,  if 
we  examine  against  the  light  a considerable  portion  of 
epidermis,  its  transparency  allows  us  to  see  many  small 
pores  separated  from  each  other  by  interstices,  and  which 
pass  through  it  in  an  oblique  direction.  It  is  only  in  the 
soles  of  the  feet  and  the  palms  of  the  hands  that  we  can- 
not make  this  observation,  which  is  owing  to  the  thick- 
ness in  those  parts.  It  is  impossible  to  distinguish  in 


EPIDERMOID  SYSTEM. 


351 


these  pores  the  absorbent  orifices  from  those  of  the  exha- 
lants,  even  when  mercury  enters  the  first  by  friction. 

The  internal  surface  of  the  epidermis  adheres  ver}’- 
closely  to  the  skin.  The  means  of  union  are  at  first  the 
exhalants,  the  absorbents  and  the  hairs,  which  in  passing 
through  the  first,  adhere  to  it  more  or  less,  and  thus  fix 
it  to  the  second,  from  which  they  arise.  By  separat- 
ing the  epidermis  by  maceration,  which  is  the  most  pro- 
per means,  we  see  on  its  internal  surface  many  small 
elongations  of  greater  or  less  length,  and  which,  when 
examined  attentively,  appear  to  be  nothing  but  the  broken 
extremities  of  exhalants  and  absorbents.  In  fact  these 
little  elongations  which  are  easily  raised  up,  and  which 
then  appear  like  small  ends  of  thread  when  they  are  of 
some  size,  but  which  exhibit  only  inequalities  when  they 
are  left  very  short,  have  all  of  them  an  oblique  course, 
and  terminate  in  the  pores  which,  we  have  said,  pass 
through  the  epidermis  to  go  to  its  surface.  Their  exist- 
ence is  sufficient,  at  the  first  inspection  and  without  the 
aid  of  a microscope,  to  enable  us  to  distinguish  the  inter- 
nal from  the  external  face  of  this  membrane.  The  spaces 
that  separate  them  are  more  or  less  large.  About  these 
spaces,  the  adhesions  are  less.  It  is  at  this  place  that  the 
small  epidermoid  vesicles  are  formed  with  -which  the 
skin  is  covered  when  plunged  into  boiling  water.  The 
depressed  interstices,  which  separate  these  vesicles,  are 
the  places  where  the  exhalants  are  and  which  have  pre- 
vented the  epidermis  from  being  raised  up.  When  ebul- 
lition is  long  continued,  they  are  detached  also. 

We  cannot  doubt  then  that  all  these  vascular  elongations 
serve  powerfully  to  unite  the  epidermis  to  the  chorion. 
How  is  the  adhesion  formed  in  their  interstices  ? I know 
not ; but  it  exists,  though  it  is  less  evident.  The  cellular 
texture,  as  I have  said,  appears  to  take  no  part  in  it. 

Every  one  knows  that  many  causes  destroy  the  adhe- 
sions of  the  epidermis,  and  raise  it  up.  These  causes  are, 


352 


EPIDERMOID  SYSTEM, 


1st,  every  severe  inflammation,  whatever  may  be  its 
species.  We  know  that  after  erysipelas,  phlegmon,  biles, 
and  cutaneous  eruptions  of  difierent  natures,  the  epidermis 
is  always  detached ; there  is  then  no  fluid  that  raises  it 
up.  The  exhalants  cannot  furnish  it,  as  they  are  full  of 
blood  ; it  is  dry  when  detached.  2d.  Various  cutaneous 
eruptions,  which  have  not  an  inflammatory  character,  as 
herpes,  &c.  also  detach  the  epidermis  at  the  place  where 
the}'’  are.  It  most  commonly  comes  oflf  then  in  the  form 
of  dry  scales  ; hence  no  doubt  the  idea  of  some  authors 
who  have  attributed  to  it  a scaly  structure,  which  neither 
observation  nor  experiment  upon  the  epidermis  in  the 
natural  slate  have  proved.  This  pealing  off  in  scales  is 
owing  to  the  same  cause  precisely  as  the  formation  of 
vesicles  which  take  place  the  instant  after  the  skin  has 
been  plunged  into  boiling  water,  viz.  to  the  greater  ad- 
hesion of  the  exhalant  vessels  which  go  to  the  epidermoid 
pores.  Observe  in  fact  that  it  is  always  in  the  space  be- 
tween these  pores  that  the  scales  are  produced,  which  do 
not  exist  in  nature,  but  which  arise  only  from  the  manner 
in  which  the  membrane  is  raised  up.  For  example,  when 
herpetic  eruptions  take  place  on  the  chin,  the  pores 
through  which  the  hairs  pass  are  not  detached  ; it  is  only  the 
epidermis  in  the  space  between  these  pores  ; now  as  these 
are  very  near  together,  these  scales  are  extremely  small ; 
they  are  almost  like  dust.  3d.  Whenever  the  epidermis 
is  raised  up  by  cutaneous  inequalities,  the  least  friction 
detaches  it  from  these  inequalities.  Hence  why,  after 
strong  dry  frictions,  a rough  skin  becomes  scaly,  whilst 
a smooth  one  experiences  no  alteration  ; it  is  this  even, 
which  in  the  external  appearance,  contributes  much  to 
the  ugliness  of  the  one  and  the  beauty  of  the  other.  4th. 
After  idiopathic  fevers,  and  even  many  affections  of  the 
internal  viscera,  the  skin  which  has  felt  the  sympathetic 
influence  of  the  disease,  becomes  the  seat  of  an  alteration 
which  without  having  any  external  sign,  is  sufficient  to 


EPIDERMOID  SYSTEM. 


353 


break  the  union  of  it  with  the  epidermis,  which  is  every- 
where raised  up.  5th.  We  know  that  the  action  of  a 
blister,  which  draws  a large  quantity  of  serum  to  the 
external  surface  of  the  chorion,  breaks  off  the  exhalants 
which  go  from  it  to  the  epidermis  ; so  that  this  serum  is 
effused  under  it  and  forms  a more  or  less  considerable  sac. 
The  water  does  not  escape  through  the  open  pores,  be- 
cause their  oblique  course  through  the  epidermis  makes 
their  parietes,  when  brought  in  contact  with  each  other 
by  the  pressure  of  the  water,  form  an  obstacle  to  it.  It 
is  for  the  same  reason,  that  though  these  pores  may  be 
very  evident,  as  I have  said,  in  a separate  portion  of  epi- 
dermis when  examined  against  the  light,  this  portion  will 
support  mercury,  without  giving  passage  to  its  particles. 
6th.  Most  of  the  preceding  means,  which  produce  their 
effect  only  by  an  alteration  of  the  vital  forces,  have  no 
effect  in  raising  the  epidermis  in  the  dead  body.  Putre- 
faction, maceration  and  ebullition  are  those  by  which  it 
is  effected.  All  act  by  breaking  the  elongations  which 
extend  from  the  dermis  to  the  epidermis,  though  the 
mechanism  of  this  rupture  is  not  exactly  known. 

II.  Organization.,  Composition,  fyc. 

Authors  have  made  many  conjectures  upon  the  struc- 
ture of  the  epidermis,  which  it  would  be  useless  to  relate 
here.  I shall  only  speak  of  what  accurate  observation 
demonstrates.  Its  thickness  is  in  general  very  uniform 
in  all  the  parts.  It  has  not  appeared  to  me  to  be  in- 
creased or  diminished,  according  to  the  varieties  of  thick- 
ness of  the  skin  on  the  back,  the  abdomen,  the  extremi- 
ties, &c.  It  is  only  on  the  soles  of  the  feet,  the  palms  of 
the  hands  and  the  corresponding  face  of  the  fingers,  that 
this  thickness  becomes  greater.  It  is  even  so  great  in 
these  places,  that  there  is  no  proportion  between  them 
and  the  other  parts  of  the  body  as  it  respects  this  mem- 
voL.  III.  45 


354 


EPIDERMOID  SYSTEM. 


brane  ; it  is  especially  towards  the  heel  that  it  exhibits 
this  character.  This  excessive  thickness  appears  to  be 
owing  to  different  layers  which  are  applied  upon  each 
other,  and  which  seem  to  be  superadded  to  the  layer  of 
the  ordinary  epidermis ; but  there  is  also  a real  differ- 
ence, though  but  little  known,  in  the  organization  ; for 
example,  Avhen  the  epidermis  has  been  removed  from 
these  parts  by  maceration,  we  cannot  see,  as  in  the  others, 
those  small  appendices  or  inequalities  regularly  scattered 
over  it,  and  which  are  the  remains  of  the  broken  exha- 
lants.  In  tb.ese  places  these  vessels  are  torn  smoother  on 
the  internal  surface  of  the  epidermis,  on  which  are  seen 
only  the  traces  of  the  wrinkles  of  which  we  have  spoken. 

I attribute  to  this  excessive  thickness  of  the  epidermis 
of  the  soles  of  the  feet  and  the  palms  of  the  hands,  the 
difficulty  and  oftentimes  impossibility  of  making  blisters 
act  in  these  places,  on  which  I have  often  applied  them 
there,  because  I thought  that  the  sensibility  being  greater, 
they  would  produce  more  effect  in  some  diseases.  The 
failure  of  my  attempts  has  compelled  me  to  renounce  them. 

This  thickness  takes  from  the  epidermis  the  trans- 
parency it  has  in  the  other  parts  ; it  is  whitish  and  opake 
even  on  the  hand  and  the  foot.  Thus  the  epidermis  which, 
in  negroes  not  being  coloured,  allows  the  blackness  of 
the  subjacent  reticular  texture  to  be  seen,  conceals  in  part 
this  blackness  in  these  places.  I have  observed  however, 
by  means  of  maceration,  that  the  less  deep  colour  of  the 
soles  of  the  feet  and  the  palms  of  the  hands  depends  also 
in  this  race  upon  this,  that  the  reticular  texture  is  really 
less  coloured.  We  might  say  that  every  thing  relates  to 
animal  sensibility  in  this  region,  the  capillary  net-work 
of  which  appeal's  to  be  less,  and  in  which  all  the  pheno- 
mena that  are  derived  from  organic  sensibility  are  much 
less  active. 

In  examining  in  this  relation  the  hand  and  foot  of  a 
Begro,  I have  been  led  to  make  upon  the  colour  of  the 


EPIDERMOID  SYSTEM, 


355 


reticular  body  some  other  experiments,  which  form  a 
short  digression.  1st.  By  plunging  into  boiling  water  a 
piece  of  the  dermis  taken  from  any  part  it  becomes  twice 
as  black,  almost  immediately  ; which  is  probably  owing  to 
this,  that  the  fibres  in  approximating  by  the  horny  hard- 
ening, bring  together  the  colouring  particles,  whence 
arises  a deeper  black.  This  phenomenon  is  very  striking, 
when  the  piece  plunged  into  the  water  is  compared  with 
one  that  has  not  been.  2d.  Maceration  for  a month  or 
two,  sometimes  removes  the  epidermis  without  the  reti- 
cular body,  the  seat  of  colour,  and  sometimes  detaches  the 
whole  together.  3d.  Being  immersed  for  some  days  in 
cold  water  produces  no  sensible  effect.  4th.  Long  contin- 
ued stewing  hardly  changes  at  all  this  colour,  after  the  deep 
tinge  that  has  been  suddenly  given  to  it.  Only  by  scrap- 
ing with  a scalpel  the  external  surface  of  the  skin  which  is 
then  reduced  to  a kind  of  gelatinous  pulp,  we  easily 
detach  the  coloured  reticular  body  from  it,  which  how- 
ever always  remains  adherent  to  a small  portion  of  the 
chorion.  5th.  Sulphuric  acid,  which  reduces  the  skin 
like  all  the  other  organs  to  a kind  of  pulpy  state,  also 
enables  us  to  remove  this  coloured  portion  easily,  which 
is  detached  in  separate  pieces,  but  the  shade  of  which  is 
hardly  altered  at  all.  6th.  Nitric  acid,  though  very  much 
weakened,  does  not  facilitate  so  much  the  removal  of  this 
coloured  portion.  It  yellows  the  internal  surface  of  the 
skin  and  the  epidermis  ; but  it  has  appeared  to  me  to  pro- 
duce but  very  little  eflect  upon  the  blackness  of  the  reticu- 
lar body.  7th.  A portion  of  the  skin  of  a negro,  im- 
mersed for  twenty-four  hours  in  a solution  of  caustic  pot- 
ash, has  not  appeared  to  me  to  have  undergone  any  altera- 
tion in  its  colour.  I have  made  the  same  observation 
when  I used  a weaker  solution.  Sth.  Putrefaction  detaches 
the  coloured  portion  of  the  skin,  sometimes  with  the  epi- 
dermis, sometimes  alone,  but  it  does  not  alter  its  colour, 
I have  not  employed  other  agents  to  ascertain  the  nature 


35G 


EPIDERMOID  SYSTEM. 


of  this  colour  of  the  skin  of  negroes.  Let  us  return  to 
the  epidermis,  Avhich  we  have  for  a moment  lost  sight  of. 

Where  it  is  veiy  thick,  as  on  tiie  concave  surface  of 
the  foot  and  the  hand,  we  see  that  it  is  evidently  formed 
by  layers  added  to  each  other,  and  which  are  separated 
with  difficulty,  because  their  adhesion  is  so  intimate. 
Everywhere  except  in  the  foot  and  the  hand,  there  is  but 
a single  la}^er  ; no  fluid  penetrates  the  epidermoid  tex- 
ture. Cut  in  different  directions  either  in  the  living  or 
dead  body,  it  allows  nothing  to  ooze  through  it.  Their 
scales  are  always  dry;  no  blood  vessel  exists  in  them. 
The  absorbents  and  exhalants  only  pass  througli  it  without 
anastomosing,  without  winding  on  its  interior  before  open- 
ing on  its  surface,  as  happens  in  the  serous  membranes, 
which  on  this  account  become  black  by  injection,  though 
but  little  blood  appears  to  enter  them  during  life.  The 
epidermis  on  the  contrary  is  never  coloured  by  this  means, 
even  when  the  injection,  being  very  fine  and  driven  with 
success,  oozes  out  on  the  external  surface  of  the  skin. 
Thus,  in  inflammation,  in  which  all  the  cutaneous  exha- 
lants are  full  of  blood  which  they  do  not  contain  in  the 
natural  state,  this  fluid  never  enters  the  epidermis,  which 
is  uniformly  disconnected  with  all  the  diseases  of  the 
subjacent  reticular  body,  and  which,  being  only  raised  up 
by  inflammation,  is  detaclied  and  afterwards  renewed. 

The  epidermis  has  evidently  no  nerves.  It  is  also  des- 
titute of  cellular  texture  ; thus  fleshy  granulations,  which 
are  formed  by  this  texture,  never  arise  from  this  mem- 
brane ; the  excrescences  of  which  it  is  the  seat  have  not 
the  character  of  the  different  tumours  which  the  cellular 
texture  especially  conti’ibutes  to  form,  such  as  fungi, 
schirri,  &c. 

From  this  it  is  evident  that  none  of  the  general  sys- 
tems common  to  all  the  organs,  enters  into  the  epidermoid 
system.  It  has  not  then  the  common  base  of  every  or- 
ganized part;  it  is  as  it  were  inorganic  in  this  respect. 


EPIDERMOID  SYSTEM. 


357 


The  epidermoid  texture  exhibits  no  fibre  in  its  interior  5 
it  has  in  general  but  little  resistance,  and  is  broken  by  a 
slight  distention,  except  on  the  fingers  and  the  hand  where 
it  resists  more,  on  account  of  its  thickness. 

The  action  of  the  air  hardly  alters  it  at  all.  Only  when 
it  is  exposed  to  it  after  having  been  removed  in  the  form 
of  a large  layer,  it  hardens  a little,  becomes  a little  more 
consistent,  and  is  torn  with  less  ease.  It  is  of  all  the  or- 
gans, next  to  the  hair  and  the  nails,  that  which  drying 
changes  the  least  in  the  natural  state.  It  also  becomes  a 
little  more  transparent  by  it;  but  resumes  its  ordinary 
state  when  again  immersed  in  water,  which  proves  that  it 
contained  a little  of  it  in  this  state.  The  action  of  the 
air,  which  is  so  quickly  efficacious  upon  the  skin  in  putre- 
faction, leaves  it  then  wholly  untouched.  It  is  only  raised 
up,  but  does  not  itself  putrify.  Separated  in  this  way  and 
washed  to  cleanse  it  of  the  fetid  substances  that  might 
adhere  to  it,  it  exhales  no  bad  odour.  Kept  a long  time 
in  moist  air,  alone  and  well  separated  from  the  neighbour- 
ing parts,  it  does  not  alter.  It  is,  next  to  the  hair  and 
the  nails,  the  most  incorruptible  of  the  animal  substances. 
I have  preserved  a foot  found  in  a cemetery,  the  skin 
and  fat  of  which  are  transformed  into  a fat,  unctuous  and 
hard  substance,  which  burns  in  the  candle,  whilst  the 
epidermis,  which  is  very  thick,  is  hardly  changed  at  all 
in  its  nature. 

The  action  of  water  upon  the  epidermis  can  be  consid- 
ered under  many  relations.  1st.  During  life  it  whitens 
it,  when  it  is  some  time  in  contact  with  it,  and  at  the 
same  time  wrinkles  it  at  different  points.  We  often  see 
this  phenomenon  in  the  hands  on  coming  out  of  a bath ; 
but  it  is  particularly  evident  after  ten  or  twelve  hours  ap- 
plication of  an  emollient  cataplasm,  in  which  the  action 
of  the  farina  is  nothing,  and  in  which  it  is  the  water  that 
produces  the  whole  effect.  This  whiteness  of  the  epider- 
mis appears  to  be  then  owing  to  its  having  really  imbibed 


358 


EPIDERMOID  SYSTEM. 


some  of  the  fluid.  It  is  the  same  phenomenon  that  takes 
place  on  the  serous,  fibrous,  membranes,  &c.  which,  hav- 
ing; become  artificially  transparent  by  dr}fing,  whiten 
again  when  immersed  in  water.  Here  the  epidermis, 
naturally  transparent,  whitens  by  the  addition  of  this 
fluid.  In  this  state  it  renders  the  sensibility  of  the  papillae 
infinitely  more  obtuse  ; I have  often  made  the  experiment 
upon  myself,  by  applying  a cataplasm  in  the  evening  and 
removing  it  the  next  morning.  When  the  water  is  evapo- 
rated wliich  the  epidermis  has  imbibed,  it  again  becomes 
transparent,  wrinkles,  resumes  its  natural  state,  and  allows 
the  sensibility  of  the  skin  to  be  again  apparent.  This 
phenomenon  is  especially  observed  upon  the  epidermis  of 
the  foot  and  the  hand,  for  it  is  not  often  as  sensible  else- 
where. 2d.  In  the  dead  body,  the  epidermis  separated 
from  tlie  skin,  and  immersed  in  water,  Avhitens  also,  but 
does  not  wrinkle.  Left  to  macerate  in  water,  it  does  not 
undergo  any  putrid  alteration.  Onl}^  there  rises  on  the 
surface  of  the  fluid  many  particles,  which  being  in  juxta- 
position, form  a whitish  pellicle  of  the  nature  of  which 
I am  ignorant.  At  the  end  of  two  or  three  months,  the 
epidermis  thus  left  in  water,  softens,  does  not  swell,  and 
is  torn  with  great  ease  ; it  is  not  reduced  to  a pulp  analo- 
gous to  that  of  the  other  organs  thus  macerated.  3d. 
When  stewed,  the  epidermis  does  not  undergo,  at  the 
instant  of  ebullition,  a horny  hardening  like  all  the  other 
organs.  Hence  why,  whilst  by  this  horny  hardening  the 
skin  is  much  diminished  in  extent,  the  epidermis  which 
remains  the  same  is  obliged  to  be  folded  in  different  direc- 
tions. When  the  ebullition  is  continued,  this  membrane 
becomes  less  resisting  and  breaks  with  great  ease,  but  is 
never  reduced  to  gelatine,  does  not  acquire  a yellowish 
colour,  and  does  not  become  elastic  like  the  organs  v/hich 
furnish  much  of  this  substance;  besides,  wo  know  that 
the  epidermoid  texture  does  not  combine  with  tannin, 
and  that  it  is  even  an  obstacle  to  it  when  it  tends  to  pene- 


EPIDERMOID  SYSTEM. 


359 


trate  the  skin.  After  long  stewing,  the  different  layers 
which  compose  the  epidermis  of  the  palm  of  the  hand, 
and  especially  that  of  the  sole  of  the  foot,  are  separated 
with  great  ease  ; this  is  the  best  way  of  seeing  this  lamel- 
lated  structure.  Between  these  layers  there  is  often 
formed  on  the  foot  small  vesicles  filled  with  serum. 

Caloric  produces  upon  the  epidermis  phenomena  wholly 
different  from  those  which  the  other  systems  experience 
from  the  contact  of  this  substance.  A portion  of  this 
membrane  well  dried  by  the  action  of  the  air,  and  ex- 
posed to  the  flame  of  a candle,  1st,  does  not  undergo 
hardly  at  all  the  horny  hardening,  as  a portion  of  skin 
does  when  thus  treated  ; 2d,  it  exhales  a fetid  odour  analo- 
gous to  that  of  burnt  horn,  and  different  from  that  of  all 
the  other  textures  when  subjected  to  the  same  experi- 
ment ; 3d,  it  burns  with  great  ease,  which  does  not  take 
place  with  any  of  the  preceding  systems  when  dried ; it 
is  often  even  sufScient  to  put  the  fire  to  it  at  one  end  to 
consume  it  entirely;  4th,  at  the  place  of  the  flame  we 
see  a blackish  bubbling  fluid,  from  which  often  escapes 
little  burning  drops,  and  which  is  very  analogous  to  that 
of  a feather  when  burnt.  It  is  evidently  an  oil  which  sup- 
ports the  combustion  by  its  great  abundance,  and  which 
does  not  appear  to  be  found  in  as  great  quantity  as  in  the 
hair  and  the  nails.  This  oil  deserves  particular  examina- 
tion ; it  is  that  which  gives  out  in  burning  so  disagree- 
able an  odour,  and  which  forms  those  burning  and  whitish 
drops  of  which  we  have  spoken.  It  appears  to  be  of  the 
same  nature  as  that  which  Bertholet  obtained  from  the 
hair  in  so  great  a proportion.  After  combustion  there  ie> 
left  a blackish  charcoal,  which  I have  not  analyzed. 

Light  does  not  a.ppear  to  have  a great  action  upon  the 
epidermis,  which  I have  found  of  the  same  colour,  in  por- 
tions of  skin  blackened  by  it,  and  in  those  which  have 
been  sheltered  from  it. 


360 


EPIDERMOID  SYSTEM. 


Nitric  acid  yellows  very  sensibly  the  epidermis,  more 
even  than  any  other  animal  substance  ; but  it  does  not 
dissolve  it  without  great  difficulty.  The  sulphuric  on  the 
contrary  acts  very  powerfully  upon  it,  especially  when  it 
is  a little  concentrated.  When  it  is  drawn  out  after  having 
been  a short  time  plunged  in,  it  is  found  to  be  very  thin, 
extremely  transparent,  and  almost  similar  in  this  respect 
to  the  pellicle  that  is  taken  from  an  onion.  This  curious 
phenomenon  has  often  struck  me.  When  left  too  long  in 
the  acid,  the  epidermis  is  finally  entirely  dissolved  in  it. 

The  alkaline  lies  dissolve  this  membrane,  but  with  dif- 
ficulty. Pure  alkali  has  a very  prompt  action  upon  it. 

Alkohol  has  no  influence  upon  the  epidennis. 

III.  Properties. 

The  epidermis  has  but  very  little  extensibilit}'’,  since 
the  least  cutaneous  tumour  can  tear  it  and  raise  it  up  in 
scales,  as  in  herpes,  or  in  larger  pieces,  as  from  a blister. 
Yet  it  is  not  entirely  destitute  of  it,  as  the  vesicle  proves 
which  is  formed  by  this  last.  Its  conti’aclility  of  texture 
is  nothing.  We  observe,  that  when  no  longer  distended, 
this  bladder  remains  flaccid  and  never  contracts. 

Every  kind  of  animal  sensibility  is  foreign  to  the  epi- 
dermis. We  know  that  it  can  be  pricked,  cut  or  torn, 
without  being  felt.  It  is  especially  on  the  palms  of  the 
hands  and  the  soles  of  the  feet  that  these  experiments  are 
easily  made.  The  thickness  of  this  membrane  is  such  in 
this  place,  that  we  can  remove  layers  of  it,  as  we  see  done 
by  those  who  try  the  edge  of  an  instrument,  that  it  is 
possible  even,  as  most  cooks  do,  to  put  it  in  contact  with 
live  coals,  and  that  it  is  not  impossible  to  carry  a red  hot 
iron  over  it.  It  is  by  this  insensibility  that  it  blunts  the 
action  of  the  acids,  the  caustic  alkalies,  and  of  all  the 
powerful  stimuli,  which  when  in  contact  with  the  dermis 
laid  bare  by  a blister,  give  excessive  pain. 


EPIDERMOID  SYSTEM. 


361 


The  epidermis  differs  from  all  the  other  organs  that  are 
destitute,  like  it,  of  aniinal  sensibility,  as  the  cartilages, 
the  tendons,  the  aponeuroses,  &c.  in  this,  that  it  is  never 
capable  of  acquiring  it;  whei'eas  the  others,  if  a little  ex- 
cited, often  take  a degree  of  it  superior  to  that  of  the 
organs  which  naturally  possess  it.  Whence  does  this 
arise  ? From  the  fact,  that  in  order  that  the  animal  sensi- 
bility may  arise  in  an  organ  it  is  necessary  that  the  rudi- 
ments of  it  should  be  there  alread)^,  and  that  this  organ 
should  enjoy  organic  sensibility,  which,  when  raised  by 
irritation  is  transformed  into  animal  ; now  the  epidermis 
appears  to  be  destitute  also  of  this  last  property,  as  well 
as  of  insensible  contractility.  In  fact,  1st,  there  is  no 
sensible  circulation  in  it.  2d.  The  exhalants  and  absorb- 
ents which  go  through  it,  are  wholly  foreign  to  it.  3d. 
No  morbid  phenomenon,'  that  supposes  organic  sensibility, 
appears  in  the  epidermis.  It  does  not  inflame  ; it  is  pas- 
sive in  all  cutaneous  affections,  and  never  partakes  of  them 
notwithstanding  its  continuity.  The  impossibility  of  in- 
flaming makes  it  an  obstacle,  wherever  it  exists,  to  cuta- 
neous adhesions,  which  cannot  take  place  until  it  is  re- 
moved. Its  internal  surface,  raised  by  a blister,  and  reap- 
plied to  the  dermis  by  the  evacuation  of  the  serum  of  the 
vesicle  by  means  of  a small  puncture,  never  unites  again. 
4th.  The  excrescences  of  which  it  is  the  seat,  as  corns, 
some  indurations,  &c.  are  inert  and  dry  like  it,  and  with- 
out internal  circulation  ; if  they  are  painful,  it  is  from  the 
pressure  upon  the  subjacent  nerves,  and  not  from  them- 
selves. 5th.  No  sensible  operation  is  performed  in  the  epi- 
dermis ; it  is  worn  incessantly  by  friction,  like  inorganic 
bodies,  and  it  is  afterwards  reproduced. 

This  continual  destruction  of  the  epidermis  has  not  suf- 
ficiently arrested  the  attention  of  physiologists.  The 
following  are  the  proofs  of  its  reality  ; 1st,  if  with  the 
blade  of  a knife,  we  scrape  strongly  its  external  surface, 
a large  quantity  of  powder  is  removed  which  sulphuric 
VOL.  III.  46 


362 


EPIDERMOID  S\S'PEM. 


acid  easily  dissolves,  and  which  is  greyish.  The  epi- 
dermis whitens  a little  in  this  place,  then  resumes  its 
colour,  especially  if  it  is  moistened.  By  scraping  again, 
we  do  not  remove  any  more  powder,  it  is  necessary  in 
oi’der  to  obtain  it,  to  wait  twelve  or  twenty  hours.  2d. 
This  substance  becomes  superabundant,  when  the  skin  has 
not  been  washed  for  a long  time.  Hence  why  those  who 
soak  their  feet  that  have  not  been  cleaned  for  a long  time, 
detach  so  great  a quantity  of  it.  It  is  especially  on  the 
sole  of  the  foot  that  this  substance  is  formed  in  abundance. 
We  often  observe  in  dead  bodies  that  it  forms  almost  a 
layer  in  addition  to  the  epidermis,  but  which  is  very 
distinct  from  it,  and  can  be  removed  with  ease.  I attri- 
bute this  circumstance  to  the  thickness  which  the  epider- 
mis has  in  this  place.  We  should  no  doubt  find  as  much 
upon  the  hand,  were  it  not  for  the  continual  friction  of 
this  part.  We  see  it  often  on  the  patients  in  hospitals, 
after  remaining  a long  time  in  bed  without  having  been 
cleansed. 

Water  naturally  removes  this  substance,  that  is  produced 
by  the  destruction  of  the  epidermis,  and,  which,  mixing 
with  the  residue  of  transpiration,  that  the  air  cannot  carry 
ofi’  by  evaporation,  renders  bathing,  as  I have  observed,  a 
natural  want.  Though  it  may  be  neither  exhaled  nor  ab- 
sorbed, and  though  its  production  may  appear  to  be  owing 
to  mechanical  friction,  yet  we  can,  in  its  relation,  consider 
the  epidermis  as  an  emunctory  of  the  body,  since  it  is 
renewed  by  a substance  coming  from  the  dermis,  as  fast 
as  it  is  removed. 

It  is  evident,  as  the  epidermis  has  no  vital  properties, 
that  it  cannot  be  the  seat  of  any  kind  of  sympathies, 
which  are  aberrations  of  these  properties.  Hence  its  life 
is  extremely  obscure,  I doubt  even  if  it  possesses  vitality. 
We  might  almost  say  that  it  is  a semi-organized  body, 
inorganic  even,  which  nature  has  placed  between  ex- 
ternal inanimate  bodies  and  the  dermis,  which  is  com- 


EPIDERMOID  SYSTEM. 


363 


pletely  organized,  in  order  to  assist  their  passage  and 
suai’d  against  their  force. 

The  epidermis  has  a property  very  distinct  from  those 
of  most  of  the  other  systems ; it  is  that  of  being  repro- 
duced when  it  has  been  removed.  It  grows  anew  and  is 
formed  again  with  an  appearance  exactly  similar  to  what 
it  first  exhibited  ; it  is  that  which  makes  it  difier  from  all 
the  other  systems,  as  the  cellular,  which  throw  out  vege- 
tations when  they  are  laid  bare,  but  which  are  only  repro- 
duced in  an  irregular  manner,  and  wholly  different  from 
their  natural  state..  How  is  the  epidermis  thus  repro- 
duced ? Is  it  the  pressure  of  the  atmospheric  air  which 
renders  the  external  surface  of  the  skin  callous  ? Is  it  the 
air,  which,  by  combining  with  the  products  which  escape 
from  this  surface,  forms  a new  compound  ? I know  not. 
What  is  certain  is,  1st,  that  this  production  is  wholly  dif- 
ferent from  that  of  the  internal  organs  ; 2d,  that  it  cannot 
take  place  except  upon  the  skin,  and  that  the  fine  pellicle 
that  covers  all  the  other  cicatrized  parts,  after  a wound 
with  loss  of  substance,  does  not  resemble  it  at  all  and  pre- 
sents even  a texture  wholly  different.  Thus  this  pellicle 
is  not  raised  up  by  the  different  means  which  raise  the 
epidermis ; thus  it  often  becomes  the  seat  of  acute  sensi- 
bility which  is  never  the  case  with  the  epidermis.  This 
is  what  takes  place  especially  in  changes  of  weather,  a 
time  in  which  the  cicatrices  become,  as  we  know,  very 
painful ; I have  often  observed,  that  not  only  the  interior, 
but  the  pellicle  even  of  the  cicatrix  are  then  sensible. 
Besides,  when  this  pellicle  is  formed,  red  blood  vessels 
evidently  penetrate  it,  whilst  nothing  similar  is  observed 
in  the  formation  of  the  epidermis. 

It  is  this  faculty  of  reproduction  which  is  put  in  action 
in  many  epidermoid  excrescences,  as  in  corns,  and  callosi- 
ties which  have  nothing  in  common  but  the  name  with 
those  which  form  the  edge  of  fistulas,  &c.  All  these  ex- 
crescences are  insensible,  without  vessels  or  nerves,  of  the 


364 


EPIOElliVIOID  SYSTEM. 


same  consistence  and  the  same  colour  as  the  epidermis; 
tliey  are  often  removed  from  it  and  afterwards  formed 
again.  It  appears  that  external  pressure  has  much  influ- 
ence upon  their  development ; too  narrow  shoes  and  the 
solid  bodies  which  are  used  on  the  hands  of  smiths  and 
other  workmen  are  the  frequent  cause  of  tliem. 

I preserved  a great  part  of  the  skin  of  a man  who  died 
at  the  Hotel  Dieu,  and  Ids  epidermis,  which  was  treble  the 
tliickness  from  his  birth  and  even  in  the  womb  of  his 
mother,  that  it  is  in  the  ordinary  state,  had  been  subject 
during  his  life  to  a continual  desquamation  which  made 
the  whole  of  it  appear  as  if  covered  with  herpes,  though 
nothing  similar  to  this  affection  existed  upon  the  dermis, 
which  was  perfectly  sound.  The  face  alone  was  exempt 
from  this  defect  of  conformation. 

The  epidermis  is  not  only  reproduced  when  the  whole 
of  it  has  been  removed,  but  also  when  the  superficial  lay- 
ers' alone  have  been  taken  away,  especially  on  the  foot 
and  the  hand  on  which  other  layers  arise  upon  those 
w’hich  the  cutting  has  laid  bare;  which  proves  that  they 
are  not,  as  has  been  said,  the  juices  of  the  reticular  body 
which  form  it  by  drying. 

IV.  Development. 

Those  who  haA^'e  thought  that  the  epidermis  is  formed 
by  pressure,  would  be  convinced  that  this  is  not  the  case 
if  they  would  examine  that  of  the  foetus,  which  is  very 
distinct,  more  even  in  proportion  than  many  other  sys- 
tems. We  observe  it  wdien  the  skin  begins  to  leave  the 
pulpy  state  of  which  we  have  spoken.  At  the  end  of  the 
fifth  month,  it  has  proportions  analogous  to  those  which 
it  will  afterwards  exhibit.  It  is  very  thick  on  the  soles  of 
the  feet  and  the  palms  of  the  hands,  and  very  thin  else- 
Avhere ; it  is  easily  detached  by  all  the  means  we  have 
pointed  out.  We  know  that  in  a foetus  that  has  died  and 


EPIDERMOID  SYSTEM. 


365 


become  putrid  in  the  womb,  it  is  found  in  great  measure 
detached.  At  the  place  of  the  umbilical  cord,  it  is  con- 
tinued in  an  insensible  manner  with  the  skin. 

At  birth,  thou2:h  it  is  in  contact  with  a fluid  that  is  new 
to  it,  it  does  not  undergo  a great  alteration  ; which  proves 
that  the  air  has  little  or  no  agency  in  its  formation.  It 
becomes  thicker  as  we  advance  in  age,  and  follows,  in 
this  respect,  nearly  the  same  proportions  as  the  skin. 
JBeyond  the  twenty-sixth  or  thirtieth  year  it  increases  no 
more.  I have  often  raised  up  in  many  places  the  epi- 
dermis of  an  old  person  ; it  has  not  appeared  to  me  to  dif- 
fer much  from  that  of  the  adult ; it  is  a little  more  sub- 
ject to  scale  off  and  it  is  a little  thicker.  In  some  miser- 
able objects  which  come  to  hospitals,  there  is  often  vermin 
in  cracks  of  the  epidermis,  whose  layers  are  afterwards 
separated  by  them  and  in  which  they  live  ; so  that  I have 
seen  the  epidermis  in  this  way  conceal  thousands  of  little 
animals,  which  were  evidently  found  between  the  layers 
of  this  membrane,  and  which  were  not  upon  the  reticular 
body  and  the  papillae.  It  is  the  only  means  that  has  shown 
to  me  the  lamellated  structure  of  the  epidermis,  in  any 
other  place  than  on  the  foot  and  the  hand,  in  which  I have 
never  seen  vermin. 

The  cracks  of  the  epidermis  in  old  age  appear  to  arise 
from  its  dryness  owing  to  the  want  of  exhalation  ; it  is 
that  which  renders  the  skin  so  rough  and  harsh.  What 
contributes  to  it  also  is,  that  as  it  has  many  inequalities  on 
account  of  its  numerous  folds,  frictions  being  more  felt  in 
these  prominent  places,  make  the  epidermis  scale  off; 
thus  in  the  adult  the  same  cause  renders  it  scaly  on  a 
tubercular  skin,  whilst  a skin  that  is  smooth  and  well 
distended  with  fat,  undergoes  every  kind  of  friction  with- 
out desquamation. 


EPIDERMOID  SYSTEM. 


36  G 


ARTICLE  SECOND. 

INTERNAL  EPIDERMIS. 


All  authors  have  admitted  the  epidermis  of  the  mu- 
cous membranes.  It  appears  that  most  have  believed  that 
it  is  only  this  portion  of  the  skin  which  descends  into  the 
cavities  to  line  them.  Haller  in  particular  is  of  this  opin- 
ion. But  the  slightest  inspection  is  sufficient  to  show, 
that  here  as  upon  the  skin,  it  forms  only  a superficial  layer 
over  the  papillary  body  and  the  chorion.  Boiling  water 
which  detaches  it  from  the  palate,  the  tongue  and  the 
pharynx  even,  enables  us  to  see  the  two  other  layers. 

I.  Epidermis  of  the  origin  of  the  Mucous  Surfaces. 

The  epidermis  is  very  distinct  upon  all  the  origins  of 
the  mucous  system,  upon  the  glans,  the  entrance  of  the 
anus,  the  urethra,  the  nasal  fossae,  the  mouth,  &c.  It  is 
demonstrated  in  these  places  b)'-  the  excoriations  that  take 
place  there,  upon  the  lips  especially,  by  dissection  with 
a very  fine  lancet,  by  the  action  of  boiling  water,  macera- 
tion, putrefaction  and  even  epispastics,  as  is  proved  by  the 
fact  that  the  ancients  employed  this  method  to  make  the 
edges  of  a hare-lip  raw.  The  delicacy  of  this  epidermis 
is  much  greater  than  on  the  skin  ; and  as  it  is  more  in 
the  interior  this  delicacy  increases.  It  is  to  this  circum- 
stance that  must  be  attributed  the  ease  with  which  different 
remarkable  modifications  are  produced  through  this  mem- 
brane, when  in  galvanic  processes,  we  arm  with  zinc  the 
surface  of  the  tongue  and  with  another  metal  the  mucous 
surface  of  the  conjunctiva,  the  pituitary  membrane,  the 
surface  of  the  rectum,  the  gums,  &c.  and  bring  in  mediate 
or  immediate  contact  these  different  metals. 


EPIDERMOID  SYSTEM. 


367 


The  mucous  epidermis  is  quickly  reproduced  when  it 
has  been  removed.  Destitute  of  every  kind  of  animal 
and  organic  sensibility,  it  is  in  this  respect,  destined  like 
the  skin,  to  defend  the  very  sensitive  papillary  body  that 
is  subjacent  to  it.  It  is  to  its  presence  upon  the  mucous 
membranes,  that  should  be  in  part  attributed  the  faculty 
they  have  of  being  exposed  to  the  air,  and  even  to  the 
contact  of  external  bodies,  without  exfoliating  or  inflaming 
as  in  preternatural  anus,  prolapsus  of  the  rectum,  &c.  ; 
whilst  the  serous  membranes  cannot  bear  this  contact 
with  impunity. 

Besides,  the  nature  of  the  mucous  epidermis  is  the  same 
as  that  of  the  cutaneous.  Submitted  to  the  action  of  the 
same  agents,  it  gives  the  same  results.  The  excrescences 
formed  on  its  surface  are  also  analogous,  though  much 
more  rare.  It  becomes  callous  by  pressure.  Chopart  re- 
lates the  ease  of  a shepherd,  whose  urethra  became  so,  from 
frequently  introducing  a small  stick  to  procure  pleasure- 
We  know  the  density  that  this  covering  has  in  the  stomach 
of  the  gallinaceous  animals,  and  in  certain  cases  in  which 
the  mucous  membranes  come  out  of  the  body  as  in  pro- 
lapsus of  the  rectum,  the  vagina,  the  womb,  &c.  Some- 
times in  those  cases  the  pressure  of  the  clothes  produces  in 
this  epidermis  a thickness  evidently  greater  than  what  is 
natural  to  it ; it  is  this  which  then  makes  these  membranes 
lose  in  part  the  bright  red  that  characterizes  them  in 
the  interior. 

II.  Epidermis  of  the  deep  seated  mucous  surfaces. 

The  epidermis  gradually  becomes  more  delicate,  and  is 
soon  almost  insensible,  on  the  internal  mucous  mem- 
branes. 1st.  In  the  stomach,  the  intestines,  the  bladder, 
the  gall-bladder,  the  vesicuiEe  seminales,  in  all  the  excre- 
tories,  &c.  the  most  delicate  instrument  cannot  raise  it  up. 
2d.  In  the  maceration  and  ebullition  of  the  mucous  sys- 


368 


EPIDERMOID  SYSTJ:M. 


tem  of  these  parts,  I have  never  seen  the  epidermis  raised 
up  on  its  surface.  3d.  I have  drawn  out  of  the  abdomen 
of  a dog  a portion  of  intestine  ; its  mucous  coat  has  been 
laid  bare  by  an  incision,  and  I have  applied  an  epispastic 
to  it ; more  redness  was  seen  upon  the  free  surface  of  this 
coat,  but  no  pellicle  was  raised  up  from  it,  4tb,  We  do 
not  see  in  preternatural  anuses,  complicated  with  inver- 
sion, excoriations  analogous  to  those  of  which  the  surface 
of  the  lips,  that  of  the  glans,  &c.  are  the  seat.  5th.  I have 
already  had  frequent  occasion  to  open  bodies  affected  with 
acute  or  chronic  catarrhs  of  the  intestines,  the  stomach, 
the  bladder,  &c.  ; now  I have  never  seen  the  epidermis 
separated  by  inflammation,  as  happens  after  erysipelas, 
phlegmon,  &c.  upon  the  cutaneous  organ.  6th.  We  do 
not  see  upon  the  deep  seated  mucous  surfaces  those  exfo- 
liations, desquamations,  &c.  so  frequent  upon  this  after 
many  alfections. 

From  all  these  considerations  it  would  appear,  that  the 
epidermis  does  not  exist  upon  the  deep  seated  mucous 
surfaces,  and  the  great  quantity  of  mucous  juices  con- 
star,  dy  poured  out  by  the  subjacent  glands,  supplies  its 
place  in  defending  the  papillae  and  the  chorion  from  the 
impression  of  substances  heterogeneous  to  the  economy, 
contained  in  the  internal  cavities.  Yet  there  is  a circum- 
stance that  would  seem  to  demonstrate  the  existence  of 
the  epidermis  upon  the  deep  seated  mucous  surfaces  ; it 
is  the  separation  of  preternatural  membranes,  which  are 
often  detached  from  these  surfaces,  and  which  may  be 
considered  as  a kind  of  epidermoid  exfoliation.  Many 
authors  give  examples  of  these  membranes  formed  either 
upon  the  bladder  and  voided  by  the  urethra,  or  upon  the 
stomach  and  oesophagus  and  thrown  up  by  vomiting,  or 
upon  the  intestines  and  expelled  with  the  alvine  evacua- 
tions ; Haller  has  collected  many  cases.  Dr.  Montaigu 
informed  me  that  he  saw  a membrane  vomited  up,  which 
formed  a sac  without  a rent,  exactly  analogous  to  that 


EPIDERMOID  SYSTEM. 


369 


of  the  stomach  whose  internal  surface  it  lined.  Desault 
saw  a sac  almost  analogous  to  the  bladder,  voided  by  a 
patient  who  was  affected  with  retention  of  urine. 

I confess  that  I have  made  no  observation  on  this  point, 
so  that  I cannot  say  what  is  the  nature  of  these  mem- 
branes. But  authors  in  general  agree  in  attributing  to 
them  a soft  and  pulpy  nature,  \vhich  does  not  appear  to 
me  to  accord  with  that  of  the  epidermis.  I have  many 
times  seen  at  the  Hotel  Dieu  white  membranes  detached 
from  the  oesophagus  after  poisoning  with  the  nitric  acid. 
But  these  membranes  are  evidently  the  superficial  portion 
of  the  mucous  organ,  which  is  disorganized,  and  thrown 
off  by  suppuration  which  takes  place  below.  It  is  thus 
that  cutaneous  eschars  fall  off  in  the  form  of  membranes 
from  large  burns ; in  this  way  the  osseous  layers  are 
formed  in  necrosis,  which  are  only  the  superficies  of  the 
bone  that  dies  and  is  detached  in  a lamellated  form. 

From  this,  the  existence  of  the  epidermis  of  the  deep 
seated  mucous  surfaces  appears  to  me  to  be  very  uncer- 
tain, and  cannot  be  admitted  till  a new  examination, 
which  will,  I think,  prove  rather  against  than  in  favour 
of  its  existence.  What  is  the  place  in  which  the  epider- 
mis terminates  that  lines  the  origin  of  the  mucous  sur- 
faces, or  if  it  exists  everywhere,  where  does  it  begin  to 
become  no  longer  apparent  from  the  action  of  our  differ- 
ent reagents  ? We  cannot,  I think,  determine  with  pre- 
cision ; it  diminishes  in  an  insensible  manner,  and  is  lost 
as  it  were  by  degrees. 


ARTICLE  THIRD. 

OF  THE  NAILS. 

All  the  fingers  have  at  their  extremity,  on  the  outer 
side  or  that  of  extension,  hard,  transparent  and  elastic  lay- 
VOL.  III.  47 


370 


EPIDERMOID  SYSTEM. 


ers,  of  the  nature  of  the  horns  of  many  animals,  and 
which  are  called  nails. 

I.  Forms,  Extent,  Relations,  S,'C, 

The  nails  of  man  differ  from  those  of  most  other  ani- 
mals, in  their  breadth  and  want  of  thickness.  The  first 
makes  them  better  adapted  to  support  the  extremity  of 
the  fingers,  which  is  broader  than  in  most  animals  for  the 
perfection  of  touch ; the  second  renders  them  less  fit  to 
serve  for  defence  or  as  a means  of  aggression. 

Most  people  cut  their  nails  even  with  their  fingers,  so 
tliat  the  length  of  these  bodies  which  is  seen  is  not  what 
is  natural  to  them.  "When  allowed  to  grow,  they  lengthen 
and  turn  over  on  the  side  of  flexion,  and  cover  entirely 
the  lower  end  of  the  fingers.  This  growth  has  a certain 
limit  which  the  nail  cannot  pass,  and  which  it  attains 
when  it  exhibits  at  its  extremity  a cutting  and  sharp  edge. 
As  long  as  this  edge  has  the  appearance  of  having  a part 
cut  off,  the  nail  continues  to  grow. 

We  usually  think  that  the  habit  of  cutting  our  nails  is 
a thing  of  mere  decorum.  But  if  we  reflect  a little  upon 
society  and  the  numerous  arts  to  which  it  gives  rise,  upon 
the  perfection,  delicacy,  precision  and  rapidity  of  the  mo- 
tions which  the  fingers  are  often  forced  to  execute,  upon 
the  necessity  of  approximating  them,  crossing  them  in  a 
thousand  different  ways,  &c.  we  shall  soon  see  that  this 
habit  is  almost  inevitably  the  result  of  the  social  state,  and 
what  appears  to  us  the  effect  of  fashion  is  that  of  neces- 
sity. The  sense  of  touch  in  man  in  a natural  state  is 
coarse  and  obscure ; it  is  only  necessary  that  he  should 
seize  objects  destined  for  his  nourishment,  his  defence, 
his  aggressions,  &c.  that  he  should  climb  especially  and 
attach  himself  to  trees  to  keep  himself  upon  them  ; now 
his  nails  are  for  this  purpose  of  great  use.  What  he  loses 
in  this  respect  in  society,  he  seems  to  gain  by  the  pre- 


EPIDERMOID  SYSTEM. 


371 


cision  and  extent  which  are  added  to  his  touch,  and  by  the 
faculty  which  the  fingers  acquire  of  distinguishing  the 
most  delicate  tangible  qualities.  In  the  first  state,  his 
hands  are  of  great  assistance  to  him  in  locomotion.  In 
the  second,  they  contribute  hardly  at  all  to  this  use,  and 
they  gain  in  the  partial  motions  of  their  fingers  what  they 
lose  in  their  motions  as  a whole,  which  become  of  less 
urgent  necessity. 

The  nail  has  three  distinct  parts  in  the  natural  state  ; 
one  posterior,  concealed  on  both  sides  by  the  integuments  ; 
another  middle,  free  only  on  one  side,  and  the  third  an- 
terior, without  adhesion  at  either  side. 

The  posterior  portion  of  the  nail  is  nearly  a sixth  part 
of  its  extent.  Its  convex  surface  adheres  very  intimately 
to  the  epidermis,  which  goes  in  the  following  manner  to 
fix  it.  After  having  covered  over  the  portion  of  the 
finger  corresponding  with  flexion,  it  is  reflected  upon  the 
concave  edge  where  the  skin  terminates  and  where  the 
nail  begins  to  become  external  ; it  commonly  forms  all 
around  this  edge  a kind  of  small  string  that  is  very  dis- 
tinct and  has  a small  groove  in  the  top  of  it,  and  which 
is  evidently  composed  entirely  of  epidermis,  since  we  can 
cut  the  whole  of  it  without  giving  any  pain,  and  which  is 
afterwards  easily  reproduced.  After  having  formed  this 
string,  which  is  in  the  form  of  a parabola,  the  epidermis 
is  again  reflected,  passes  between  the  skin  and  the  nail, 
and  is  glued,  if  we  may  so  say,  to  the  concave  surface  of 
the  latter,  without  being  intermixed  with  it;  for  we  can 
remove  it  with  ease  by  scraping  with  a scalpel.  So  that 
the  dermis  which  covers  the  superior  portion  is  really  be- 
tween two  layers  of  epidermis.  After  having  thus  fixed 
the  nail,  and  having  arrived  at  its  posterior  edge,  the  epi- 
dermis is  continued  and  identified  as  it  were  with  this 
edge,  whose  evident  delicacy  and  softness  approximate  it 
in  nature  to  this  membranous  layer.  Hence  it  follows 
that  without  the  adhesion  of  the  epidermis  to  the  nail, 


372 


EPIDERMOID  SYSTEM. 


there  would  be  between  them,  a kind  of  cul-de-sac.  Some 
authors  have  thought  that  the  extensor  tendon  is  extended 
as  far ; but  it  is  easy  to  see  that  it  does  not  go  beyond  the 
tubercle  which  terminates  behind  the  phalanx.  The  nail 
does  not  reach  this  tubercle,  there  is  a space  of  three  lines 
between  them.  The  concave  surface  of  the  posterior 
portion  of  the  nail  corresponds  with  the  same  substance 
as  the  middle  portion. 

This  middle  portion  is  bare  on  its  convex  surface,  which 
is  smooth,  whitish  behind  where  this  colour  forms  a kind 
of  half  moon,  reddish  in  the  greater  part  of  its  extent,  a 
colour  which  is  foreign  to  it  and  which  it  derives  from 
the  subjacent  texture.  Upon  the  sides,  the  skin  covers 
this  surface  a little,  and  terminates  afterwards  by  continu- 
ing the  concave  and  free  edge  of  which  we  have  spoken. 
The  epidermis  forms  also  in  this  place  a small  string 
which  is  continued  on  each  side  \yith  that  pointed  out 
above ; then  it  unites  to  the  nail  and  adheres  to  its  lateral 
edges  with  which  it  is  identified.  The  concave  surface 
of  this  middle  portion  is  fixed  in  front  by  the  epidermis, 
which,  after  having  covered  the  extremity  of  the  fingers, 
and  having  arrived  at  the  place  where  the  nail  ceases  to 
be  free,  is  separated  from  the  dermis,  and  adheres  to  the 
whole  length  of  the  nail  in  a curved  line  ; then  by  mix- 
ing with  it,  it  seems  to  form  its  internal  lamina.  The 
dermis  on  the  contrary  is  continued  on  the  convexity  of 
the  last  phalanx,  has  there  a remarkable  consistence,  a 
reddish  appearance,  and  a texture  like  pulp  and  wholly 
different  from  what  is  observed  elsewhere  ; more  vessels 
run  through  it;  there  is  no  distinct  space  in  it,  and  no 
elongation  goes  from  it  to  the  surface  of  the  nail  of  which 
the  epidermis  forms  a part.  We  do  not  see  on  this  sur- 
face, as  on  those  of  the  other  parts  of  the  epidermis,  those 
threads,  which  are  the  remains  of  the  broken  exhalants 
and  of  which  we  have  spoken ; thus  the  sweat  never 
passes  through  the  nail.  There  is  neither  any  oily  oozing 


EPIDERMOID  SYSTEM. 


373 


upon  its  surface  ; whence  it  follows  that  water  is  not  form- 
ed into  little  drops  on  the  exterior  of  its  horny  laminae. 
Hence  the  nail  is  evidently  insulated  from  all  the  other 
organs  except  the  epidermis,  with  which  it  is  continued 
on  its  concave  face  and  especially  on  its  posterior  and 
lateral  edges.  Thus  observe  that  when  collections  of  pus 
or  other  affections  have  broken  this  continuity  behind  or 
on  the  sides,  the  whole  of  the  nail,  though  unaffected  in 
the  middle  falls  off. 

The  free  or  anterior  portion  of  the  nail  is  of  a length 
which  it  is  difficult  to  determine.  I have  never  seen  it 
allowed  to  take  its  natural  growth.  I have  only  observed 
that  if  it  is  permitted  to  grow  to  a considerable  size,  we 
see  evidently  that  it  has  a greater  thickness  than  the  pos- 
terior and  middle  portion.  In  general,  the  thickness, 
resistance  and  hardness  of  the  nail  increase  in  a gradual 
manner  from  the  posterior  to  the  anterior  part ; we  shall 
now  examine  to  what  this  is  owing. 

II.  Organization  ; Properties,  <§-c. 

In  order  to  observe  the  organization  of  the  nails  advan- 
tageously, it  is  necessary  to  take  those  that  are  very  dis- 
tinct, as  those  of  the  great  toe,  the  thumb,  &c.  We  then 
see  evidently  that  a single  lamina  occupies  the  whole  of 
their  convex  surface.  Behind,  this  lamina  exists  alone  ; 
hence  the  extreme  thickness  of  the  nails  at  this  place. 
But  as  we  examine  towards  the  front,  we  see  new  laminae 
successively  added  to  it,  on  the  concave  surface  ; so  that 
the  nail  becomes  successively  thicker.  These  laminae  can 
be  easily  raised  up  layer  by  layer.  The  most  anterior 
are  the  shortest.  They  often  exhibit  upon  the  concave 
surface  of  the  nail  an  infinite  number  of  very  evident 
small  striae,  all  longitudinal  and  parallel,  and  which  make 
us  attribute  to  it  a fibrous  texture.  At  other  times  this 
arrangement  is  less  evident. 


374 


EPIDERMOID  SYSTEM. 


What  is  tlie  nature  of  the  laminss  which  form  the  nails  ? 
I believe  that  they  are  almost  precisely  the  same  as  the 
epidermis.  What  proves  it  is,  1st,  that  the  most  super- 
ficial is  evidently  continued  with  it  by  its  edges  ; there  is 
no  intermediate  agent  between  them.  2d.  I have  already 
observed  that  the  nails  are  detached,  and  then  regene- 
rated exactly  like  the  epidermis.  They  have  two  modes 
of  increase ; one  in  length,  when  we  cut  their  extremi- 
ties ; the  other  in  thickness,  when  we  detach  only  a lami- 
na, which  is  soon  formed  again.  When  the  whole  of 
the  nail  comes  off,  all  the  portion  of  the  dermis  which 
covers  yie  back  of  the  last  phalanx,  contributes  at  the 
same  time  to  form  it  anew  by  its  external  surface.  3d. 
There  is  the  same  obscurity  in  the  vitality  of  the  nails  as 
in  that  of  the  epidermis.  No  trace  of  animal  sensibility 
is  discoverable  in  them.  The  excruciating  pain  that  is 
experienced  when  they  are  pulled  out  arises  solely  from 
the  sensibility  of  the  subjacent  pulpy  texture  ; it  is  from 
the  same  cause  as  in  pulling  out  the  hair.  There  is  no 
organic  sensibility,  no  internal  circulation  and  conse- 
quently no  heat  inherent  in  the  texture  of  the  nails  ; thus 
the  horns  of  animals  are  nearly  of  the  same  degree  of 
temperature  as  the  atmosphere,  whilst  some  external  pro- 
ductions with  evident  vital  forces,  though  raised  up  like 
horns,  have  a temperature  equal  to  that  of  the  body_ 
Such  are  the  combs  of  the  cock  of  our  country,  and  those 
which  are  more  striking  of  the  cock-turkey.  Compare 
these  excrescences  with  those  on  the  feet  of  these  animals, 
which  are  horny,  and  the  difference  of  temperature  is 
evident.  4th.  The  nails  give  out  when  burning  a dis- 
agreeable odour,  analogous  to  that  of  the  epidermis  under 
the  same  circumstances  j they  exhibit  then  the  same  phe- 
nomena. Their  combustion  is  supported,  like  that  of  the 
epidermis,  by  an  oil  of  which  they  contain  a great  quan- 
tity. 5th.  If  maceration  and  stewing  do  not  produce 
upon  the  nails  that  want  of  consistence,  that  Icind  of  brit- 


EPIDERMOID  SYSTEM. 


375 


tleness,  if  I may  so  express  myself,  which  they  produce 
upon  the  epidermis,  it  appears  to  be  owing  only  to  their 
greater  solidity.  6th.  The  action  of  the  nitric,  sulphuric 
acids,  &c.  has  exhibited  to  me  nearly  the  same  phenomena 
as  upon  the  epidermis. 

Every  thing  then  appears  to  establish  the  most  exact 
analogy  in  the  composition,  organization  and  properties 
of  the  nails  and  the  epidermis.  There  is  no  doubt  a dif- 
ference of  principles  between  them,  since  the  appearance 
is  not  the  same,  and  since,  though  many  epidermoid 
layers  may  be  in  juxta  position  as  on  the  soles  of  the  feet 
and  the  palms  of  the  hands,  they  do  not  exhibit  tbe  form 
and  texture  of  the  nails  ; so  that  we  cannot  consider  these 
as  mere  layers  of  epidermis  applied  to  each  other.  Chemists 
must  ascertain  what  these  differences  are,  which  are  cer- 
tainly very  slight.  Thus  nature  often  employs  indif- 
ferently the  two  organs  for  the  same  uses ; it  is  thus  that 
on  the  sole  of  the  foot  of  man  and  many  analogous  species, 
there  is  a thick  epidermis ; whilst  on  the  feet  of  animals 
with  hoofs,  we  see  a horny  substance  of  the  nature  of  the 
human  nail. 

An  evident  proof  of  the  slight  degree  of  internal  motion 
which  is  going  on  in  the  epidermis  and  the  nails,  of  the 
kind  of  inertia  in  which  they  are  in  relation  to  the  con- 
stant motion  of  composition  and  decomposition,  which 
constitutes  nutrition,  and  of  the  insensibility  which  they 
exhibit  to  various  excitants,  is  the  ease  with  which  they 
are  penetrated  by  different  colouring  substances,  and  the 
very  long  time  they  retain  them.  We  know  this  effect 
with  regard  to  the  nails  of  dyers.  Many  savage  people 
who  paint  the  face,  various  parts  of  the  body,  and  often 
even  the  whole  of  the  external  surface  of  the  body,  pre- 
serve for  a long  time,  without  a new  coat,  the  colour 
which  they  have  artificially  given  themselves.  I have 
removed  the  epidermis  of  a portion  of  skin  of  the  arm  of 
a dead  body,  which  was  coloiu’ed  blue  during  life ; this 


376 


EPIDERMOID  SYSTEM. 


colour  was  not  only  on  the  surface  of  the  membrane,  but 
penetrated  the  whole  of  it,  like  a piece  of  cloth  that  had 
been  soaked  in  it.  Yet  the  pores  were  as  evident  as  be- 
fore, and  the  sweat  could  pass  through  them ; I presume 
this  secretion  goes  on  as  usual  in  savages  who  paint  the 
skin.  Thus  the  cloth  which  is  immersed  in  a dye,  has 
not  its  pores  closed  by  it.  I may  make  use  of  this  com- 
parison, as  the  epidermis  and  the  nails  are  really  species 
of  inorganic  bodies.  Lay  any  organ  bare  and  paint  it  in 
this  way  ; the  colour,  together  with  the  contact  of  the 
air  will  irritate  and  inflame  it,  and  the  suppuration  arising 
from  this  inflammation  will  soon  throw  out  the  colouring 
particles,  which  nutrition  would  have  done,  if  inflamma- 
tion had  not.  There  is  a means  however  which  can  per- 
petuate the  colour,  even  upon  organs,  which,  very  sensi- 
ble like  the  skin,  are  constantly  subject  to  the  double  nu- 
tritive motion  ; it  is  that  of  using  the  colours  with  a red 
hot  iron.  It  is  in  this  way  I am  convinced  that  the  letters 
or  coloured  figures  which  most  soldiers  mark  upon  them- 
selves, with  a red  hot  pin,  have  their  seat  not  only  in  the 
epidermis,  but  also  in  the  chorion  itself. 

Development . 

The  nails  have  in  the  foetus  a very  considerable  con- 
sistence, whilst  the  skin  is  still  pulpy  ; but  their  tenuity 
is  then  extreme.  But  they  thicken  and  acquire  greater 
consistence  as  the  foetus  increases  in  size.  They  have 
not  at  birth  a length  proportionable  to  what  they  are  after- 
wards to  have.  They  do  not  extend  beyond  the  ends  of 
the  fingers  which  are  often  much  tlie  longest ; so  that  it  is 
not  till  after  birth  that  they  are  bent  over  and  exceed  the 
fingers  in  length,  for  both  of  these  would  be  useless  in 
the  womb  of  the  mother,  as  there  is  nothing  there  for  the 
foetus  to  seize  upon.  Their  transparency  allows  us  evi- 
dently to  see,  at  the  moment  of  birth,  first  the  black  colour 
of  the  blood  which  before  circulated  in  the  artenes,  and 


EPIDERMOID  SYSTEM. 


377 


then  the  vermilion  colour  which  respiration  suddenly  im- 
parts to  it.  As  we  advance  in  age,  the  nails  grow  in  the 
same  proportions  as  the  epidermis,  but  they  have  nothing 
peculiar  in  their  growth.  In  old  people  they  become  ex- 
tremely thick. 

These  organs  experience  during  life  those  diseases  only 
which  are  analogous  to  those  of  the  epidermis.  These 
are  excrescences,  augmentations  of  size,  &c.  and  other 
productions,  the  texture  of  which  is  precisely  the  same  as 
that  of  the  nail,  and  in  which  there  is  neither  more  sen- 
sibility, nor  more  circulation,  nor  more  heat,  nor  more 
life ; a remarkable  character  which  distinguishes  them 
from  those  tumours  which  arise  upon  the  other  organs 
with  very  active  vitality,  as  upon  the  skin,  the  muscles, 
&c.  tumours  the  texture  of  which  is  very  different  from 
that  of  the  organs  which  have  produced  them,  and  which 
most  usually  have  properties  entirely  different.  But  the 
epidermoid  excrescences  are  in  every  respect  analogous 
to  the  epidermis. 


VOL.  III. 


48 


V*  : 


■-  ;{'•• 


J 


PILOUS  SYSTEM. 


THE  adjective  by  which  I characterize  this  system,  is 
derived  from  the  latin  substantive  which  signifies  the  or- 
gans of  which  it  is  composed.  Hair  is  found  less  gene- 
rally upon  man  than  upon  most  other  animals.  It  forms 
upon  them  a kind  of  covering  external  to  the  skin,  which, 
lessening  in  part  the  contact  of  external  bodies,  makes  the 
cutaneous  animal  sensibility  perform  a less  important  part, 
and  establishes  less  numerous  relations  between  these 
bodies  and  them.  External  life  is  then,  in  this  respect, 
more  limited  in  them  than  in  man,  in  whom  a delicate 
epidermis  and  a few  hairs  thinly  scattered  over  it,  sepa- 
rate the  organ  of  feeling  from  surrounding  objects,  the 
least  impression  of  which  is  felt,  and  which,  ownng  to 
this,  keep  the  animal  sensibility  in  permanent  actiwty ; 
thus  man  is  designed  to  live  more  without  than  within 
himself.  The  pleasures  of  raproduction  and  digestion 
constitute  exclusively  the  happiness  of  animals.  That  of 
man  is  in  part  the  result  of  them ; but  an  order  of  plea- 
sures wholly  different,  purely  intellectual  and  in  relation 
only  with  external  sensations,  enlarges  immensely  by  its 
presence,  and  contracts  by  its  absence,  the  field  of  this 
happiness. 


380 


PILOUS  SYSTEM. 


The  hair  of  man  covers  especially  the  cranium,  some 
parts  of  the  face,  the  front  of  the  trunk,  the  genital  or- 
gans, the  extremities,  &c.  The  quantity  varies  remarka- 
bly, as  well  as  the  form,  length,  &c.  In  order  to  form  an 
accurate  idea  of  it,  we  shall  now  consider  it  separately  in 
the  dilferent  organs,  we  shall  then  treat  of  its  general  or- 
ganization, properties  and  development. 


ARTICLE  FIRST. 

EXAMINATION  OP  THE  PILOUS  SYSTEM  IN  THE  DIFFER- 
ENT REGIONS. 

This  system  must  be  considered  on  the  head,  the  trunk 
and  the  extremities. 

I.  Pilous  System  of  the  Head. 

The  head  is  the  part  of  the  body  in  which  this  system 
predominates  ; it  covers  the  whole  cranium  and  defends 
it  against  the  impression  of  external  bodies,  as  the  hairy 
coat  of  quadrupeds  defends  them.  Thus  this  part  is  the 
least  capable  of  exercising  tlie  sense  of  touch,  either  from 
the  obscurity  of  the  animal  sensibility  arising  from  this 
hairy  covering,  or  because  its  convex  form  allows  it  to  be 
in  contact  with  external  bodies  only  by  a small  surface. 

The  face  is  less  generally  covered  with  hairs,  though 
many  are  found  upon  it,  especially  in  men.  This  part, 
in  which  in  a very  small  space  are  collected  the  greatest 
number  of  our  means  of  communication  with  external 
objects,  viz.  the  organs  of  taste,  smell,  sight  and  even 


PILOUS  SYSTEM, 


381 


hearing,  has  but  very  little  to  do  with  the  sense  of  touch, 
on  account  of  its  villous  arrangement.  Its  form  is  also 
badly  adapted  to  this  sense.  The  mouth  which  is  flat- 
tened cannot  be  applied  to  external  bodies.  Thus  whilst 
the  snout  which  is  elongated  in  most  quadrupeds,  per- 
forms the  double  function  of  first  feeling  all  bodies,  turn- 
ing them  in  various  directions  in  order  to  ascertain  their 
tangible  qualities,  and  then  of  seizing  them  for  nourish- 
ment, the  mouth  of  man  serves  only  for  this  last  use  ; it  is 
the  hands  wdiich  are  destined  for  the  first.  Thus  observe 
that  all  animals,  even  the  most  of  those  with  clavicles, 
almost  uniformly  direct  their  snout  towards  the  earth, 
whilst  the  mouth  of  man  is  naturally  destined  to  an  op- 
posite position. 

Of  the  Hairs  of  the  Head. 

They  occupy  upon  the  cranium  all  the  space  which 
corresponds  with  the  occipital,  parietal,  the  squamous 
portion  of  the  temporal  and  a small  portion  of  the  frontal 
bones.  Their  limits  do  not  vary  on  the  sides  ; they 
always  correspond  above  the  ear.  Behind,  they  some- 
times go  down  upon  the  superior  part  of  the  neck ; at 
others,  they  do  not  extend  beyond  the  head.  In  apply- 
ing blisters  on  the  ligarnentum  nuchse,  we  observe  in  this 
respect,  almost  as  many  varieties  as  there  are  subjects. 
We  know  how  variable  these  limits  are  in  front.  Some- 
times extended  lower  down,  sometimes  carried  higher  up, 
sometimes  describing  a curved  line,  and  at  others  forming 
a real  triangle  the  anterior  point  of  which  corresponds 
with  the  median  line,  they  have  really  nothing  constant. 

These  inequalities  alone  determine  the  breadth  or  nar- 
rowness of  the  forehead,  whilst  its  degrees  of  inclination 
depend  solely  upon  the  bone  which  forms  it.  It  is  in  this 
way  that  the  hair  contributes  a little  to  the  expression  of 
the  face  ; I say  a little,  for  it  is  less  to  the  breadth  of  the 
forehead  than  to  its  approximation  to  a perpendicular, 


382 


PILOUS  SYSTEM. 


that  we  attach  the  ideas  of  majesty  and  greatness  which 
characterize  heroes  and  gods.  The  poets,  as  we  know, 
have  particularly  celebrated  the  forehead  of  the  god  of 
thunder.  Observe  in  relation  to  this  subject  that  there  is 
a great  difference  between  that  which  expresses  majesty 
or  abjectness  in  the  face,  froni  that  which  serves  there 
to  express  the  passions.  It  is  the  osseous  structure  of 
this  region  and  the  degree  of  inclination  resulting  from 
this  structure,  which  serve  for  the  first  use,  and  it  is  espe- 
cially the  muscular  motions  which  contribute  to  the 
second.  Why  ? Because  majesty,  grandeur,  &c.  are  espe- 
cially connected  with  the  extent  of  the  understanding,  and 
the  understanding  has  its  seat  in  the  brain,  and  because 
the  various  capacities  of  the  cranium,  which  contain  this 
organ,  and  which  correspond  with  its  various  degrees  of 
development,  have  inevitably  an  influence  upon  the  dif- 
ferent dimensions  of  the  face.  Now  as  the  bony  struc- 
ture is  a thing  constant  and  invariable,  the  air  of  majesty 
or  abjectness  remains  always  imprinted  upon  the  face. 
On  the  contrary,  the  passions  which  especially  aflfect  the 
epigastric  organs,  which  afterwards  excite  the  facial  mus- 
cles, have  necessarily  a transitory  expression. 

The  number  of  hairs  is  very  variable  on  the  same  sur- 
face. In  some  people  they  are  very  close  together  and 
even  all  touch  ; in  others  more  thinly  scattered,  they 
allow  in  part  the  skin  of  the  cranium  to  be  seen  in  their 
interstices,  a circumstance  which  is  either  owing  to  origi- 
nal conformation,  or  to  a disease  which  makes  them  fall 
out  in  part.  They  have,  like  the  nails,  a determinate 
growth  which  they  do  not  exceed.  We  know  but 
little  of  the  limit  of  this  growth.  Yet  we  have  seen  them 
reach  to  the  waist,  the  thighs,  and  the  legs  even.  It  ap- 
pears that  in  women  they  have  a greater  growth  ; we 
might  say,  that  nature  has  compensated  this  sex  in  this 
way  for  the  want  of  hair  in  many  other  parts.  Floating 
upon  the  shoulders,  the  breast,  the  trunk,  &c.  they  form 


PILOUS  SYSTEM. 


3S3 


in  the  natural  state  a sort  of  protection  from  the  injuries 
of  the  air  and  the  light.  Their  extent  evidently  proves 
that  man  was  destined  to  an  erect  attitude.  In  fact,  in 
the  attitude  of  quadrupeds,  they  would  trail  much  upon 
the  earth,  and  form  an  obstacle  to  motion.  The  hair  of 
no  animal,  I believe,  in  a natural  attitude  retards  his  pro- 
gress so  much,  as  the  hair  of  man  then  would. 

Man,  who  opposes  nature  in  every  thing,  has  made  it 
a habit  in  most  societies  to  cut  the  hair,  the  beard,  &c. 
By  common  people,  it  is  considered  merely  a thing  of 
fashion ; by  the  ph)^sician,  as  a practice  w'hich  has  per- 
haps a greater  influence  than  is  thought  upon  the  func- 
tions. In  fact,  in  the  natural  state  when  the  pilous  sys- 
tem has  once  acquired  its  growth,  it  no  longer  exhibits  the 
constant  motion  of  composition  and  decomposition.  On 
the  contrary,  in  man  who  cuts  it,  it  is  constanth^  the  seat 
of  this  motion  and  of  that  of  growth.  This  practice  per- 
petuates then  the  phenomena  which  lake  place  m them 
in  infancy,  and  consequently  keeps  up  there  a more  active 
work,  which  perhaps  is  performed  at  the  expense  of  that 
of  many  other  parts. . 

The  natural  difference  of  the  hair  has  much  influ- 
ence upon  its  length ; that  which  is  smooth  and  curls  but 
little  is  in  general  the  longest.  The  more  it  has  the  oppo- 
site characters,  the  shorter  it  is,  as  is  proved  by  that  of 
negroes  and  those  white  people  whose  hair  curls  like 
theirs. 

The  tenuity  of  the  hair  is  very  great,  yet  its  resistance 
is  in  proportion  very  considerable.  There  is  no  part  in 
the  economy,  not  even  those  of  the  fibrous  system,  which 
can  support  so  great  a weight  in  proportion  to  its  size. 
Thus  woven  strings  of  hair  would  have  an  enormous 
resistance,  if  they  were  sufficiently  long  to  be  employed 
for  different  uses. 

The  colour  of  the  hair  varies  remarkably  according  to 
country,  latitude,  climate,  temperature,  &c.  This  colour 


3S4 


PILOUS  SYSTEM. 


is  even,  like  that  of  the  skin,  a characteristic  attribute  of 
the  different  human  races.  Naturalists  have  been  much 
occupied  with  this  subject,  and  I refer  to  their  works. 

In  our  climate  the  principal  colours  are  black,  flaxen 
and  bright  red.  They  are,  as  it  were,  the  three  general 
types  to  which  may  be  referred  many  particular  shades. 
The  black  has  under  it  the  brown,  the  chesnut,  &c.  The 
flaxen  is  connected  on  the  one  hand  with  the  brigrht 
red  and  on  the  other  with  the  chesnut.  The  bright  red 
Avhich  touches  the  flaxen  by  one  of  its  extreme  shades, 
goes  by  an  opposite  shade  to  the  natural  colour  of  certain 
flames. 

All  physicians  have  considered  the  colour  of  the  hair 
as  among  the  characters  of  the  temperaments.  Black  in- 
dicates strength  and  vigour.  The  figure  of  a wrestler 
with  flaxen  hair  would  be  almost  ridiculous.  This  colour 
is  the  attribute  of  weakness  and  delicacy  , it  floats  upon 
the  head  of  figures  which  painters  have  made  strangers 
to  the  great  passions,  to  powerful  and  heroic  deeds  ; it  is 
found  upon  the  figures  of  young  people,  in  pictures  where 
laughter,  sport,  grace  and  pleasure  preside  over  the  sub- 
jects. These  two  coloiu’s,  black  and  flaxen,  as  well  as 
their  secondary  shades,  are  found  distributed  among 
women  in  nearly  equal  proportion  ; now  reflect  upon  the 
kind  of  sentiment  this  sex  inspires  according  to  the  colour 
of  the  hair,  without  regard  to  any  other  consideration, 
and  you  will  see  that  a woman  with  flaxen  hair  creates  a 
sentiment  which  beauty  and  weakness  united  seem  to 
dictate.  The  epithets  that  we  employ  express  this  double 
attribute.  On  the  contrary,  the  term  brunette  announces 
in  her  that  it  designates,  a mixture  of  force  and  beauty. 
Beauty  is  then  a common  gift  which  attracts  us,  but 
which,  difierently  modified  by  external  forms,  attracts  us 
by  touching,  interesting  and  exciting  us.  Eyes  in  which 
langour  is  depicted,  are  frequently  associated  with  flaxen 
hair;  whilst  black  hair  is  almost  always  met  with,  in 


riLOUS  SYSTEM. 


385 


those  whose  vivacity  and  sparkling  seem  to  proclaim  an 
excess  of  life  which  seeks  to  be  diffused. 

Habit  which  accustoms  us  to  every  thing,  changes  our 
taste  in  regard  to  the  colour  of  the  hair,  as  it  does  to 
that  of  our  dress.  Black,  flaxen  and  their  numerous  shades 
are  in  turns  fashionable  in  France  ; and  as  the  organiza- 
tion does  not  change  with  our  taste,  we  have  contrived 
artificial  hair ; a happy  means,  which  seems  to  subject  to 
our  inconstancy  the  invariable  course  of  nature,  and  which, 
changing  at  our  will  the  expression  which  the  physiog- 
nomy borrows  from  the  hair,  can  at  every  instant  exhibit 
man  under  forms  which  fashion  extols  to  day,  and  which 
ridicule  pursues  tomorrow.  Now  among  these  number- 
less variations  which  succeed  each  other  among  us  in  the 
fashion  of  the  hair,  bright  red  and  its  various  shades  never 
find  a place.  Most  people  have  a decided  aversion  to  it. 
It  is  almost,  in  our  eyes,  a mal-formation  to  be  born  with 
it.  This  opinion  is  too  general  not  to  have  some  real 
foundation.  The  principle  appears  to  me  to  be  the  usual 
connexion  between  the  hair  and  the  temperament  and  of 
course  the  character  which  results  from  this  ; now  the 
kind  of  character  connected  with  this  kind  of  hair  is  not 
commonly  the  happiest,  though  there  are  many  exceptions 
to  this  principle,  which  is  proverbial.  Another  reason 
for  the  aversion  to  hair  of  a bright  red,  is  that  the  oily 
fluid  which  lubricates  it  often  exhales  a fetid  odour  foreign 
to  the  other  kinds  of  hair. 

What  is  the  relation  that  can  exist  between  the  hair 
and  the  character?  Has  the  first  an  influence  upon  the 
second  ? No;  the  following  is  the  way  in  which  it  should 
be  considered.  Every  man  has  his  peculiar  kind  of  organ- 
ization and  constitution.  This  forms  the  temperament ; 
now,  to  each  kind  is  attached  on  the  one  hand  this  or  that 
species  of  hair,  and  on  the  other  the  predominance  of 
some  internal  viscera,  which  though  less  apparent  is  not 
less  real.  This  predominance  disposes  evidently  to  certain 
VOL.  III.  49 


3S6 


PILOUS  SYSTEM. 


passions,  which  are  the  principal  attributes  of  character ; 
then  the  colour  of  the  liair  and  character  are  two  differ- 
ent results  from  the  same  cause,  viz.  constitution  ; but  one 
has  no  influence  upon  the  other. 

The  hair  coming  out  of  the  cutaneous  pores  has  such  a 
direction,  that  that  of  the  anterior  part  of  the  cranium  is 
almost  always  oblique  in  front,  and  tends  to  fall  over  the 
forehead  ; that  of  the  middle  and  posterior  part  pierces 
the  skin  perpendicularly,  and  that  of  the  posterior  and  in- 
ferior part  traverses  it  obliquely,  so  as  to  fall  naturally 
down  the  length  of  the  posterior  part  of  the  neck.  It  is 
the  same  with  that  of  the  sides,  which  its  direction  as 
well  as  its  weight,  carries  upon  the  region  of  the  ear  which 
it  covers. 

Eyebrows. 

Upon  the  arch  which  borders  the  orbit  above,  is  found 
a collection  of  hairs  forming  a portion  of  a circle  more  or 
less  evident,  which  shades  the  eye  and  defends  it  from  the 
too  powerful  impression  of  the  rays  of  light.  The  hairs 
of  the  eyebrows  are  thicker  together  in  persons  of  dark 
complexion,  than  in  those  of  light.  More  numerous 
within,  they  sometimes  unite  together  the  two  eyebrows 
upon  the  nasal  prominence,  and  thus  shade  the  root  of  the 
nose.  Fewer  without,  they  there  cause  the  eyebrow  to 
terminate  in  a point.  All  are  obliquely  directed  from 
within  outwards.  Sometimes  tow'ards  the  internal  side, 
they  go  perpendicularly  forwards.  Their  length  is  scarcely 
more  than  half  an  inch  ; they  do  not  exceed  this  except  in 
some  extraordinary  cases.  Their  colour  is  usually,  though 
not  invariably,  the  same  as  that  of  the  hair.  They  arc 
firmer,  more  resisting  and  larger  than  the  hairs  of  the  head. 
If  they  were  longer  they  would  curl  like  the  hairs  on  the 
genital  parts,  of  the  nature  of  which  they  partake. 

The  eyebrows  enjoy  two  evident  motions.  1st.  They 
are  depressed  and  carried  inwards,  by  forming  over  the 


PILOUS  SYSTEM. 


387 


eye  a very  evident  arch.  2d.  They  are  raised  up  and 
separated  from  each  other,  by  expanding  the  parts  around 
the  orbit.  The  length  between  the  extremes  of  these  two 
motions  is  nearly  an  inch.  The  first  motion  takes  place 
to  defend  the  eye  from  a ver.j4^bright  light.  It  expresses 
also  the  melancholy  and  gloomy  passions ; hence  the  rea- 
son no  doubt  why  the  same  word  is  applied  to  the  moral 
state  of  the  mind,  and  to  the  row  of  hairs  of  which  we 
are  treating.  Observe  on  this  subject  that  the  sanguineous 
and  choleric  temperaments,  which  are  the  most  disposed 
to  the  passions  which  make  the  eyebrows  contract,  are 
precisely  those  in  which  the  hairs  that  compose  them  are 
found  in  general  the  most  evident.  The  second  motion 
enables  us  to  receive  upon  the  region  of  the  orbit  a great 
quantity  of  the  rays  of  light ; it  allows  us  to  raise  the 
upper  eyelid  to  a great  extent  in  order  to  open  the  eye 
wide,  which  the  first  evidently  prevents.  It  expresses 
also  the  gay  passions,  those  which  dilate  the  face.  Paint- 
ers have  studied  more  than  anatomists,  the  different  de- 
grees of  elevation  and  depression  of  the  eyebrows. 

Eyelashes. 

Upon  both  eyelids  there  exists  a small  row  of  hairs,  a 
little  longer  than  those  of  the  eyebrows,  of  the  same 
nature  as  them,  directed  obliquely  forwards,  crossing  each 
other  when  the  two  eyelids  are  brought  together,  and 
serving  to  defend  the  eye  from  the  small  particles  floating 
in  the  air.  In  general  they  do  not  curl ; when  they  do 
and  turn  towards  the  eye,  an  irritation  ensues,  and  they 
must  be  cut  off.  Sometimes  a bad  direction  is  the  cause 
of  this  irritation. 

I would  remark  on  the  subject  of  the  eyelashes,  that  all 
the  openings  of  communication  with  the  interior,  as  those 
of  the  meatus  auditorius  externus,  the  nose  and  the  anus, 
and  oftentimes  also  the  orifices  of  the  lactiferous  tubes, 
are  surrounded  with  a great  number  of  hairs  which  defend 


388 


PILOUS  SYSTEM. 


these  openings  from  external  bodies.  Around  the  mouth 
the  beard  takes  the  place  of  these  hairs ; the  urethra  has 
none,  but  the  prepuce  at  its  orifice  is  instead  of  them. 

Beard. 

The  males  of  most  animals  are  distinguished  from  the 
females  by  some  external  productions.  The  comb  of  the 
cock,  the  mane  of  the  lion,  the  horns  of  the  stag,  &c.  are 
examples  of  these  distinctive  characters.  In  man,  the 
beard  is  the  principal  attribute  of  the  male.  It  occupies 
all  the  chin,  the  sides  of  the  face,  both  lips  and  the  supe- 
rior part  of  the  neck.  It  leaves  the  cheeks  bare  as  well 
as  the  parts  around  the  eyes  ; thus  observe  that  it  is  there 
that  the  passions  are  principally  depicted,  the  expression 
of  which  would  be  concealed  by  the  hairs,  if  the  lower 
part  of  the  face  was  the  seat  of  them. 

The  beard,  not  so  long  in  general  as  the  hair  of  the 
head,  is  longer  than  that  of  every  other  part  of  the  body. 
It  is  very  commonly  of  the  colour  of  the  first,  though 
more  rarely  flaxen  and  is  more  frequently  of  a bright  red, 
which  it  often  is  in  persons  with  flaxen  hair.  The  nature 
of  the  hairs  of  the  beard  is  the  same  as  that  of  the  hairs 
of  the  genital  parts,  the  eyebrows,  &c.  They  curl,  are 
stiffer,  more  resisting  and  uniformly  less  oily  than  the 
hair  of  the  head. 

The  quantity  of  beard  varies  remarkably  in  different 
men.  Those  in  whom  it  is  abundant  and  of  a deep  black 
are  in  general  strong  and  vigorous.  Observe  also  that 
the  strongest  males  in  the  different  species  of  animals  are 
those,  in  whom  the  external  production  which  distin- 
guishes them  from  the  females,  is  the  most  conspicuous. 
We  might  :.a}'  that  this  characteristic  production  is  the  in- 
dex of  the  strength  or  weakness  of  their  constitution.  A 
small  lion  has  not  a noble  mane ; great  horns  belong  to  a 
well  made  stag,  and  long,  twisted  ones  to  a good  formed 
ram.  Observe  that  it  is  not  the  same  with  the  other  hairs 


PILOUS  SYSTEM. 


389 


common  to  the  two  sexes.  Often  in  a weak  man,  those 
of  the  arms,  the  thighs,  &c.  are  as  evident  and  even  more 
numerous,  than  in  the  most  muscular. 

The  habit  of  cutting  the  beard  as  most  Europeans  do, 
of  preserving  it  like  the  Asiatics  and  of  dressing  it  in  dif- 
ferent ways  like  the  Chinese,  gives  a different  expression 
to  the  face  which  characterizes  the  people.  A masculine, 
vigorous  physiogomy  which  expresses  strength  and  ener- 
gy, cannot  be  deprived  of  this  external  attribute  without 
losing  a part  of  its  character.  That  of  the  Orientals  ex- 
hibits an  appearance  which  coincides  with  the  strength  of 
their  bodies,  and  forms  a contrast  with  the  effeminacy  of 
their  manners.  I do  not  know  if,  in  consulting  the  his- 
tory of  the  different  people  who  allow  their  beard  to 
grow,  and  that  of  nations  who  cut  it,  we  might  not  be 
tempted  to  believe  that  muscular  force  is  to  a certain  ex- 
tent connected  with  its  existence,  and  that  this  force  is 
always  diminished  a little  when  we  are  constantly  de- 
prived of  it.  Every  one  knows  the  vigour  of  the  an- 
cients, that  of  the  people  with  long  beards,  and  that  even 
of  certain  men  who,  among  us,  allow  their  beards  to  grow 
in  conformity  with  the  laws  of  monkish  institutions.  No 
doubt  many  causes  may  make  weakness  exist  with  a 
beard  ; but  in  a general  view  I think  we  can  admit  that 
there  is  a certain  relation  between  it  and  strength.  Take 
from  a cock  his  comb,  which  is  the  characteristic  of  the 
male,  as  the  beard  is  that  of  man,  and  he  will  lose  strength. 
I am  persuaded  that  we  might  take  from  the  lion  a part 
of  his  power  by  taking  away  his  mane.  We  know  the 
result  of  the  experirhents  of  Russel  upon  the  castration 
of  stags ; their  horns,  after  this  operation  have  grown  in 
an  irregular  manner,  or  have  not  even  grown  at  all.  This 
external  attribute  of  the  male  in  this  species,  appears  as 
we  know  at  the  period  of  virility,  when  the  vital  forces 
are  increased.  It  is  the  same  with  the  human  beard. 
This  coincidence  would  alone  prove  that  the  use  of  this 


390 


PILOUS  SYSTEM. 


last  is  to  serve  for  an  external  character  to  the  male  sex. 
The  eunuch,  whose  powers  are  feeble,  loses  also  often- 
times much  of  his  beard. 

Such  are  our  prejudices  in  regard  to  the  idea  we  form 
of  beauty,  that  we  ridicule  what  is  really  and  absolutely 
so,  for  that  is  certainly  so  which  indicates  organic  perfec- 
tion. A peacock  without  his  tail  of  emeralds,  a ram 
or  a stag  without  their  horns,  displease  us  ; why  does 
not  man  without  his  beard  ? 

II.  Of  the  Pilous  System  of  the  Trunk. 

The  hairs  on  the  trunk  are  very  variable.  Some  men 
appear  as  it  were  shaggy,  whilst  others  are  almost  with- 
out hairs.  There  are  more  of  them  generally  on  the  an- 
terior than  on  the  posterior  part  of  the  trunk.  It  is  prin- 
cipally along  the  linea  alba  and  upon  the  chest,  that  they 
are  found  in  man.  This  last  part  is  in  general  destitute 
of  them  in  woman,  v/ho  has  usually  very  few  on  the 
trunk. 

Both  sexes  have  a very  considerable  quantity  on  the 
genital  parts.  They  are  there,  as  I have  said,  of  the 
nature  of  the  beard.  Less  frequently  flaxen  than  the 
hair  of  the  head,  as  frequently  of  a bright  red,  they  are 
most  usually  black.  They  are,  next  to  the  beard,  the 
longest  hairs.  They  have  generall}’^  no  determinate  direc- 
tion; each  hair  almost  has  a different  one.  Few  animals, 
like  man,  exhibit  this  excess  of  hair  upon  the  genital  parts. 
There  is  a great  difference  in  individuals  as  to  its  quantity. 
The  blackness  and  abundance  coincide  in  general  with 
strength. 

III.  Pilous  System  of  the  Extremities. 

Man  has  many  hairs  upon  the  whole  surface  of  his  ex- 
tremities. The  proportion  of  number  is  nearly  the  same 


PILOUS  SYSTEM. 


391 


in  all ; but  the  length  varies  very  much  ; in  some,  they 
form  only  a down ; in  others,  they  are  a little  longer ; 
whilst  in  others,  they  are  nearly  of  an  inch  in  length, 
reach  over  each  other,  and  give  the  extremities  a shaggy 
appearance. 

At  the  top  of  the  superior  extremities,  there  is  in  the 
hollow  of  the  axilla  a collection  of  hairs  which  are  longer 
than  the  others,  and  are  nearly  of  the  nature  of  those  of 
the  genital  parts.  Nothing  similar  is  seen  on  the  inferior 
extremities. 

The  pilous  system  does  not  exist  on  the  internal  part  of 
the  arm  and  fore-arm  in  many  men,  in  whom  we  see  it 
only  behind  and  on  the  sides.  It  is  more  uniform  on  the 
inferior  extremities.  The  back  of  the  foot  and  hand 
always  have  hairs.  They  are  never  seen  on  the  sole  of 
the  one  or  the  palm  of  the  other ; a circumstance  of  essen- 
tial advantage  to  the  perfection  of  touch. 


ARTICLE  SECOND. 


ORGANIZATION  OF  THE  PILOUS  SYSTEM. 

Whatever  varieties  exist  in  the  form,  size  and  arrange- 
ment of  the  hairs,  their  organization  is  nearly  the  same  in 
all.  We  shall  now  examine  this  organization  in  a general 
manner.  Chirac,  Malpighi  and  all  anatomists  since  them, 
have  explained  very  well  in  some  respects,  and  very  badly 
in  others,  the  structure  of  the  hairs  of  the  head,  which  is 
nearly  the  same  as  that  of  all  the  other  hairs.  The  follow- 
ing is  what  careful  dissection  has  shown  me  concerning  it. 


392 


PILOUS  SYSTEM. 


I.  Origin  of  the  Hairs. 

The  hairs  of  the  head,  and  in  general  all  the  hairs,  arise 
from  a sub-cutaneous  fat,  or  the  cellular  texture  of  the 
parts  which  are  destitute  of  this  fluid.  Each  is  contained 
at  its  origin,  in  a kind  of  small  membranous  canal,  the 
nature  of  which  is  perfectly  unknown  to  me,  and  whose 
transparent  parietes  allow  the  hair  to  be  plainly  seen, 
when  we  have  separated  them  with  a delicate  scalpel  from 
the  surrounding  parts.  This  small  cylindrical  canal  ac- 
companies the  hair  to  the  corresponding  pore  of  the  skin, 
insinuates  itself  into  this  pore,  passes  through  it,  extends 
to  the  epidermis  and  is  intermixed  there  with  the  texture 
of  this  membrane,  but  goes  no  further.  The  length  of 
this  canal,  and  consequently  of  the  course  which  the  hair 
runs  under  and  in  the  skin,  is  nearly  five  lines  in  the 
hairs  of  the  head.  There  is  no  adhesion  between  the  hair 
and  the  internal  surface  of  this  small  canal,  except  at  the 
enlarged  base  of  the  first  where,  it  receives  its  nourish- 
ment. Thus,  by  opening  the  canal  at  this  place,  and 
destroying  its  adhesions  there,  the  hair  becomes  free,  and 
is  drawn  from  without  inwards  with  great  ease,  by  taking 
hold  of  its  enlarged  end  with  small  forceps.  In  this  way, 
the  canal  is  insulated.  I have  thus  dissected  and  sepa- 
rated, upon  a surface  of  two  inches,  a very  great  number 
of  these  canals  which  appear,  when  nothing  but  them  is 
left  on  the  internal  surface  of  the  skin,  like  so  many  small 
elongations  of  it. 

Are  there  vessels  and  nerves  in  this  small  cylindrical 
sac  which  contains  the  origin  of  the  hairs  ? We  see  dis- 
tinctly elongations  going  to  its  external  surface,  especially 
towards  its  extremity  opposite  to  the  skin;  but  dissec- 
tion does  not  teach  us  the  nature  of  these  elongations.  I 
have  never  been  able  to  trace  them  to  a neighbouring 
vessel  or  nerve.  Haller  has  not  been  more  successful, 


PILOUS  SYSTEM. 


393 


though  he  speaks  of  authors  v/ho  have  traced  nerves  to 
the  origin  of  the  hairs.  I presume  however  that  these 
elongations  are  especially  vascular.  Is  there  a fluid  be- 
tween the  origin  of  the  hair' and  its  covering?  By  open- 
ing the  latter,  nothing  escapes,  though  some  authors  have 
pretended  the  contrary.  Besides,  if  this  fluid  is  in  the 
form  of  dew,  as  upon  the  serous  surfaces,  it  cannot  be 
distinguished. 

It  is  in  the  middle  of  this  small  cylindrical  sac,  of 
which  I have  just  spoken,  that  the  origin  of  the  hair  is 
found.  We  see  at  its  extremity  an  enlargement  often- 
times almost  insensible,  at  others  very  evident,  though 
always  less  than  has  been  said.  This  enlargement  is  of 
the  same  colour  and  nature  as  the  hair  itself.  It  adheres 
to  the  canal  very  probably  by  the  vessels  and  perhaps  the 
nerves  it  receives  from  it.  The  hair  which  arises  from 
it  goes  through  its  canal  without  adhering,  as  I have  said, 
to  its  parietes,  passes  with  it  through  the  oblique  pore 
of  the  dermis,  leaves  it  at  the  epidermis,  and  goes  out- 
ward. 

All  authors  say  that  the  hair  does  not  pierce  the  epi- 
dermis, but  only  raises  it  up,  and  that  this  forms  a sheath 
which  accompanies  it  to  its  extremity.  This  assertion  is 
incorrect ; in  fact,  1st,  the  hair  is  as  thick  in  its  canal  of 
origin  as  it  is  out  of  it.  2d.  This  canal  being  opened  at 
its  extremity  opposite  to  the  skin,  we  can  draw  out  of  it, 
as  I have  said,  the  whole  hair  with  great  ease,  and  with- 
out the  least  resistance  ; which  would  not  be  the  case 
however  if  the  covering  of  the  epidermis  was  to  be 
broken.  It  appears  that  from  the  enlargement  of  its  ex- 
tremity, the  hair  has  no  adhesion  either  in  the  subcuta- 
neous canal,  or  in  its  passage  through  the  skin,  or  the  epi- 
dermis. 3d.  If  the  cutaneous  epidermis  was  raised  up  to 
cover  the  hair,  this  would  have  a treble  thickness,  unless 
this  epidermis  became  wonderfully  thin  upon  it.  4th. 
We  do  not  see  this  pretended  rising  up  by  drawing  out  a 
VOL.  III.  50 


394 


\ 

PILOUS  SYSTEM. 


hair  of  the  head  ; on  the  contrary  a depression  exists  at 
the  place  where  this  comes  out.  The  cutaneous  epider- 
mis furnishes  nothing  tlien  to  the  hairs,  though  the  nature 
of  them  may  be  in  part  the  same  as  its  own,  and  it  is 
proper  to  consider  them  as  uniform  in  their  structure  from 
one  extremity  to  the  other. 

Under  the  skin,  through  it  and  out  of  it,  the  hair  is 
composed  of  two  distinct  parts.  One  external,  forms  a 
canal  which  extends  from  the  enlargement  of  the  dermoid 
extremity  to  the  opposite  one  ; the  other  internal,  which 
composes  as  it  were  the  medulla  of  it,  is  of  an  unknown 
natu  -e. 


II.  External  Covering  of  the  Hairs. 

The  external  covering  of  the  hair  appears  to  be  of  the 
nature  of  the  epidermis.  It  has  in  fact  almost  all  the 
attributes  of  it.  1st.  The  hairs  of  the  head  burn  exactly 
like  this  membrane,  give  out  when  burning  an  analogous 
odour,  and  leave  after  combustion  a similar  kind  of  coal  ; 
now  it  is  principally  to  the  external  portion  that  these 
phenomena  are  owing.  2d.  Water  penetrates  the  hairs 
with  great  ease  ; hence  very  useful  hygrometers  can  be 
constructed  with  them  ; now  the  same  is  true  of  the  epi- 
dermis ; and  moistened  hairs  in  foggy  weather  present  in 
this  respect  a phenomenon  analogous  to  that  of  the  epidei’- 
mis  softened,  wrinkled  and  whitened  by  the  contact  of  a 
cataplasm.  3d.  It  is  by  means  of  the  epidermoid  cover- 
ing that  the  hairs  are  foreign  to  life,  that  they  are  insen- 
sible and  never  become  the  seat  of  any  acute  or  chronic 
affection.  4th.  This  covering  is  white,  whatever  may  be 
the  colour  of  the  hairs.  The  cause  of  the  colour  resides 
in  the  internal  medulla  ; thus  the  epidermis  of  negroes 
and  that  of  white  people  difi'er  but  very  little.  Hence 
why  when  the  internal  substance  of  the  hair  has  dis- 
appeared, the  canal  remaining  alone  exhibits  a more  or 


PILOUS  SYSTEM. 


395 


less  evident  whiteness.  5th.  In  this  state,  though  the  in- 
terior of  the  hair  may  be  dead,  the  epidermoid  exterior, 
which  is  independent  of  it,  preserves  most  commonly  the 
faculty  of  growing  when  it  is  cut;  thus  the  cutaneous 
epidermis  is  truly  foreign  to  all  the  subjacent  diseases  of 
the  skin.  6th.  I presume  that  it  is  this  covering  which 
gives  to  the  hairs  of  the  head  the  property  of  remaining 
so  long  uninjured.  When  removed  far  from  the  access  of 
the  air,  they  remain  unaltered  for  ages  ; they  have  not  in 
them  the  principle  of  decomposition  of  the  other  animal 
substances.  They  never  become  putrid  either  in  air  or 
water.  Thus  we  have  seen  that  the  cutaneous  epidermis 
never  undergoes  putrefaction,  which  seizes  upon  the  sub- 
jacent parts. 

It  appears  however  that  the  hairs  are  more  unalterable 
than  the  epidermis,  and  that  there  is  even  a difference  of 
nature  between  them.  In  fact,  1st,  maceration  and  ebulli- 
tion, which  make  the  epidermis  very  easy  to  be  broken, 
though  they  soften  it  but  little,  leave  the  hairs  with  their 
usual  resistance,  unless  carried  to  degrees  that  I have  not 
tried.  By  boiling  and  macerating  them  comparatively 
with  the  epidermis,  we  easily  make  this  observation.  2d. 
The  acids  act  less  efficaciously  upon  the  hairs  than  upon 
this  membrane  ; but  the  alkalies  dissolve  them  with  as 
much  and  even  more  ease.  3d.  A thread  of  epidermis 
of  equal  thickness  would  be  incomparably  less  resisting 
than  a hair.  4th.  The  hairs  can,  like  the  epidermis,  be 
painted  of  different  colours ; but  they  do  not  retain  them 
so  long,  and  on  this  account  the  colour  must  be  renewed 
oftener. 

Some  modern  authors  have  said  that  there  is  detached 
from  the  external  covering  of  the  hairs  a kind  of  scales 
which  form  as  it  were  little  branches  to  them.  We  do 
not  see  these  elongations.  However  the  experiment  men- 
tioned by  Fourcroy,  and  which  consists  in  this,  that  by 
rubbing  a hair  between  the  fingers,  it  is  raised  like  the 


596 


PILOUS  SYSTEM. 


heads  of  some  species  of  grain  in  the  direction  from  its 
base  to  its  point,  this  experiment,  I say,  appears  to  prove 
the  existence  of  these  insensible  elongations,  which  per- 
form also  an  essential  part  in  the  adhesion  of  the  hairs  of 
the  head  to  each  other,  an  adhesion  that  is  such  that  when 
they  have  remained  a long  time  without  being  separated, 
as  in  long  diseases,  it  is  only  done  with  the  greatest 
difficulty. 

Sometimes  the  hairs  are  bifurcated  in  a very  evident 
manner  at  their  extremity. 

It  is  the  greater  or  less  thickness  of  the  epidermoid 
covering  of  the  hairs,  which  constitutes  the  different  nature 
of  them.  Thick  and  compact  on  the  genital  parts,  the 
chin,  &c.  it  is  less  easily  penetrated  with  water,  and  ren- 
ders the  hairs  more  elastic  there  and  more  capable  of 
curling.  Loose  and  thin  in  the  hairs  of  the  head,  it  makes 
them  more  smooth,  and  gives  them  more  sensibly  the  pro- 
perty of  the  hygrometer.  It  is  the  f>eculiar  nature  of  this 
external  covering,  which  gives  to  the  hairs  of  the  head 
and  the  hair  of  negroes  the  character  which  distinguishes 
them. 

From  what  we  have  just  said  it  is  evident  that  the  ex- 
ternal covering  of  the  hairs  of  the  head  is  the  part  of  them 
which  is  essentially  inert  and  foreign  to  life.  It  is  not 
the  same  with  their  internal  substance. 

III.  Internal  Substance  of  the  Hairs. 

This  substance  is  the  most  important;  it  is  this  which 
essentially  characterizes  the  hairs,  which  I should  have 
ranked  in  the  epidermoid  system,  if  they  had  nothing  but 
their  external  covering,  as  is  the  case  when  they  become 
white. 

We  are  entirely  ignorant  of  the  nature  of  this  internal 
substance.  It  can  only  be  presumed  that  there  are  ex- 
tremely delicate  vessels  inclosed  in  the  common  epider- 


PILOUS  SYSTEM. 


397 


inoid  covering  containing  a colouring  substance,  which 
stagnates  in  these  vessels,  or  at  least  is  subjected  in  them 
to  a very  slow  nutritive  motion.  Among  these  vessels, 
do  any  of  them  as  on  the  skin,  open  outwards  to  throw 
off  fluids?  Many  physiologists  have  thought  so,  and  on 
this  account  they  have  considered  the  hairs  as  real  emunc- 
tories.  I do  not  believe  that  we  have  any  anatomical 
data  upon  this  point ; but  the  plica  polonica,  a singular 
disease  in  which  the  hair  when  cut  pours  out  blood,  evi- 
dently proves  that  they  have  exhalants  in  a natural  state, 
which  then  becoming  enlarged  and  dilated,  pour  out  a 
fluid  that  they  before  refused  to  admit.  Besides,  there 
is  no  doubt  that  the  pilous  exhalants,  infinitely  less  active 
than  the  cutaneous,  are  a much  less  copious  emunctory. 
As  to  the  absorptions  which  some  have  pretended  are 
made  by  the  vessels  of  the  hairs,  I think  that  nothing  can 
prove  them. 

From  what  we  have  just  said  upon  the  internal  sub- 
stance of  the  hairs,  it  appears  that  it  has  a true  analogy 
with  the  reticular  body  of  the  skin,  and  that,  like  it,  it 
arises  from  two  sorts  of  vessels,  one  in  which  the  colour- 
ing matter  stagnates,  the  other  which  givms  passage,  in 
some  cases  at  least,  to  fluids,  and  in  which  there  is  con- 
sequently a kind  of  circulation. 

The  colouring  substance  of  the  hairs  has  some  analogy 
with  that  of  the  skin.  Thus  we  observe  that  the  first, 
like  the  second,  is  blacker  in  warm  climates  and  nearer 
the  equator  than  in  colder  ones  ; thus  red  hair  is  fre- 
quently found  with  freckles  which  are  more  or  less  abun- 
dantly spread  upon  the  skin  of  some  people,  and  which 
are  evidently  seated  in  the  reticular  body,  as  I have  ascer- 
tained in  many  patients  who  had  these  marks,  and  in 
whom  the  epidermis  was  raised  up  either  by  erysipelas 
or  a blister.  The  acids  however  change  the  colour  of  the 
hair  more  than  they  do  that  of  the  skin  of  negroes.  The 
muriatic  whitens  at  first  the  hairs  of  the  head  which 


39S 


PILOUS  SYSTEM. 


become  yellow  in  drying  ; the  nitric  yellows,  and  the 
sulphuric  leaves  them  black. 

That  which  especially  interests  us  in  the  internal  sub- 
stance of  the  hairs,  is  the  real  vitality  which  it  enjoys, 
and  w'hich  essentially  distinguishes  it  from  the  external 
covering.  It  is  to  this  character  that  must  be  referred 
the  following  phenomena. 

1st.  The  difierent  passions  of  the  mind  have  a remark- 
able’ influence  upon  the  internal  substance  of  the  hairs. 
Often,  in  a very  short  time,  grief  has  changed  the  colour 
of  it,  and  whitened  it  by  occasioning  no  doubt  the  re- 
absorption of  the  fluid  contained  in  the  small  capillary 
vessels.  Many  authors  have  related  facts  of  this  kind. 
Some,  even  Haller,  have  doubted  them.  But  I know  at 
least  five  or  six  instances  in  which  a discoloration  has 
taken  place  in  less  than  eight  days.  The  hair  of  a person 
of  my  acquaintance  became  almost  entirely  white  in  the 
course  of  a night  upon  the  receipt  of  melancholy  intelli- 
gence. In  these  changes,  the  epidermoid  covering  re- 
mains the  same,  preserves  its  texture,  its  nature  and  its 
properties ; the  internal  substance  only  is  altered.  It  is 
said  that  terror  can  make  the  hair  stand  an  end  ; painters 
express  it  even  by  this  external  attribute  ; I know  not  to 
w’liat  extent  we  should  give  belief  to  this  phenomenon 
which  I have  never  seen  ; but  it  is  an  opinion  too  gene- 
rally received  not  to  have  some  real  foundation.  Now  if 
fear  acts  so  powerfully  upon  the  hair,  if  it  can  give  it  a 
real  motion,  is  it  astonishing  that  grief  and  pain  should 
suddenly  change  the  fluids  that  are  found  in  it,  and  de- 
prive it  even  of  these  fluids  ? 

2d.  The  plica  polonica,  of  which  I spoke  just  now,  in 
which  the  hairs  of  the  head  become,  when  they  are  cut  or 
even  when  they  are  not,  the  seat  of  a bloody  exhalation, 
and  in  which  they  have  a remai’kable  excess  of  life,  evi- 
dently resides  in  the  internal  substance  ; the  epidermoid 
covering  has  no  connexion  wnth  it.  Some  authors  even 


PILOUS  SYSTEM. 


39& 


say  that  this  in+ernal  substance  acquires  sometimes  a fleshy 
nature ; then  their  covering  is  raised  up  in  scales. 

3d.  We  know  the  danger  of  cutting  the  hair  after  many 
acute  diseases.  I have  alread}'  seen  a melancholy  in- 
stance of  it.  Many  physicians,  Lanoix  in  particular,  have- 
related  others.  Now,  to  what  are  these  accidents  owing? 
It  is  certainly  not  to  the  contact  of  the  air,  from  which 
the  hair  defends  the  head ; for  these  accidents  take  place, 
though  the  head  may  be  covered.  It  can  only  be  owing 
to  this,  that  the  growth  of  the  hairs  that  are  cut,  calls  to 
these  organs  a vital  activity  which  the  internal  viscera 
soon  sympathetically  feel  ; hence  the  pains  of  the  heady 
the  affections  of  the  eyes,  &c.  observed  in  these  cases. 
It  is  a species  of  active  sympathy  exerted  by  the  hair 
upon  the  viscera  ; now,  every  organ  which  sympathizes 
has  a real  vitality,  and  enjoys  very  distinct  vital  proper- 
ties. The  epidermis  never  takes  part  in  sympathies,  be- 
cause it  is  almost  completely  inert,  is  hardly  organized, 
is  not  at  the  level  of  the  other  organs,  and  cannot  conse- 
quently correspond  with  them.  The  danger  of  cutting 
the  hair  after  severe  sickness,  gives  me  opportunity  to 
observe  that  it  is  often  as  dangerous  to  remove  suddenly 
the  vermin  from  the  heads  of  children  during  these  dis- 
eases. I have  seen  three  or  four  instances  of  accidents 
from  this  cause. 

4th.  The  hairs  not  onl)>’  influence  other  systems,  but 
are  also  influenced  by  them.  This  is  what  we  often  see 
after  acute  diseases,  in  which  the  roots  sympathetically 
aSected,  repel  the  fluids  that  come  to  nourish  them,  die, 
and  the  hairs  fall  out.  Observe  that  this  falling  out  of 
the  hair  very  rarely  takes  place  at  the  same  time  with  the 
desquamation  of  the  epidermis  ; which  proves,  that  the 
generally  admitted  opinion  of  the  origin  of  the  external 
covering  of  the  hairs  is  entirely  false,  and  that,  though 
very  analogous  to  the  epidermis,  this  covering  does  not 
arise  from  it,  as  I have  said. 


400 


PILOUS  SYSTEM. 


5th.  Many  animals  lose  at  one  season  of  the  year  their 
hairy  covering,  which  is  afterwards  reproduced ; now  the 
period  of  its  regeneration  is  often  that  of  many  diseases, 
and  almost  always  that  of  a greater  weakness  than  at  other 
times.  We  might  say  that  the  nutritive  work  which  then 
calls  to  the  exterior  much  vital  force,  diminishes  tliis 
force  in  the  other  regions.  Man  is  not  subject  to  these 
annual  renewals  of  the  external  productions  which  cover 
his  body,  like  birds,  many  quadrupeds,  reptiles,  &e.  It 
is  a cause  of  less  diseases.  In  fact,  a thousand  different 
causes  would  no  doubt  have  frequently  deranged  these 
renewals  in  society,  as  a thousand  causes  disturb  the  men- 
strual evacuation,  &c.  ; hence  the  various  diseases  we 
escape  by  the  want  of  this  renewal.  Man  is  in  general 
subjected  to  fewer  causes  of  natural  revolutions,  than  most 
animals. 

6th.  Heat  and  cold  have  also  oftentimes  an  influence 
upon  the  internal  substance  of  the  hairs.  We  know  that 
in  some  animals,  as  rabbits,  hares,  &c.  they  become  white 
in  the  winter  and  resume  their  original  colour  in  the  sum- 
mer. 

' 7th.  A short  time  after  painting  the  hairs  of  the  head 
black,  a fashion  now  more  common  in  France  than  at  the 
period  in  which  they  powdered  them,  there  is  often  ex- 
perienced pains  in  the  head  and  a swelling  of  the  hairy 
scalp,  though  the  skin  has  been  in  no  way  concerned, 
has  not  been  pulled,  and  the  hair  only  has  been  affected. 

It  follows  from  all  we  have  just  said,  that  the  hairs 
analogous,  by  their  external  covering,  to  the  epidermis; 
foreign  by  means  of  it,  if  we  may  so  say,  to  life,  belong  to 
it  much  more  particularly  by  their  internal  substance,  a 
substance  whose  nature  is  yet  but  little  known,  as  I have 
already  said.  What  moreover  evidentl}'  proves  this  asser- 
tion, is  that  the  phenomena  of  which  I have  just  spoken, 
and  to  which  I could  add  many  others,  cease  to  be  evi- 
dent in  persons,  in  whom  the  hairs  having  become  white, 


PILOUS  SYSTEM. 


401, 


have  no  longer  any  thing  but  the  epidermoid  covering, 
the  internal  substance  having  in  part  disappeared  ; parti- 
cular observation  proves  this.  It  may  be  however  that 
in  this  case  that  portion  alone  of  this  internal  substance, 
corresponding  to  the  colour,  is  destroyed,  whilst  that  which 
is  the  seat  of  the  exhalations  continues  to  live  as  usual ; 
and,  in  this  respect,  white  hairs  may  experience  vital 
phenomena,  of  which,  I believe,  there  are  a few  examples. 
But  all  this  is  subordinate  to  the  future  experiments, 
which  will  elucidate  the  pilous  structure  more  than  it 
now  is. 


ARTICLE  THIRD. 


PROPERTIES  OP  THE  PILOUS  SYSTEM- 


The  hairs  experience  but  a slight  degree  of  the  horny 
hardening  when  exposed  to  the  action  of  caloric.  They 
then  turn  in  various  directions,  curl  and  twist ; but  this 
arises  from  a cause  entirely  different  from  that  of  the 
horny  hardening  of  the  other  organs.  The  caloric  then 
removes  the  moisture  with  which  the  hairs  are  constantly 
penetrated,  and  thus  approximates  their  particles.  Thus 
when  the  hair  is  moistened  by  fog,  a bath,  &c.  the  curls 
disappear.  The  oily  substances  that  are  used  at  the  toilet, 
give  a coat  that  is  insoluble  in  water,  and  preserve  the 
curling,  by  preventing  it  from  penetrating  the  hairs. 
Some  time  after  the  head  has  been  washed,  they  curl 
more,  as  we  have  had  occasion  to  observe  since  the  Gre- 
cian head  dresses  have  been  in  fashion  among  us.  This 
51 


VOL.  III. 


403 


PILOUS  SYSTEM. 


at  first  appears  to  be  contradictory,  but  it  is  not  so.  In 
fact  by  then  rubbing  the  hairs  much,  the  unctuous  sub- 
stance is  removed,  which  always  surrounds  them,  or  this 
substance  combines  with  the  soap,  if  the  water  contains 
it,  as  is  often  the  case ; by  this  means  it  easily  penetrates 
the  hairs,  the  pores  of  which  remain  open,  and  by  after- 
wards evaporating  with  the  fluids  that  were  already  there, 
and  which  the  unctuous  substance  retained,  it  leaves  these 
organs  more  dry  than  they  were,  and  consequently  more 
disposed  to  curl. 

A proof,  that  it  is  the. epidermoid  covering  which  thus 
imbibes  the  moisture  that  it  afterwards  loses  in  the  state 
which  succeeds  the  curling,  is,  that  the  detached  epider- 
mis can  be  curled  with  a hot  iron,  and  afterwards  render- 
ed supple  by  soaking  it  in  water. 

The  contractility  and  extensibility  of  texture  are  very 
indistinct  in  the  hairs  ; it  is  their  resistance  which  pre- 
vents their  rupture  ; they  can  hardly  be  stretched  at  all. 

They  have  no  animal  sensibility  when  pulled  ; the  pain 
that  arises  from  it  has  its  seat  especially  in  the  skin 
through  which  they  pass.  Thus  when  drawn  opposite  to 
their  direction,  we  suffer  much  more  than  by  stretching 
them  in  the  direction  of  their  pores.  I do  not  deny  how- 
ever that  these  elongations,  which  fix  their  origin  to  the 
neighbouring  parts,  may  be  also  the  seat  of  pain  when 
the  hairs  are  pulled.  These  organs  have  no  animal  con- 
tractility. 

The  organic  properties  certainly  exist  in  their  internal 
substance.  The  changes  which  this  substance  undergoes 
can  only  depend  on  the  different  alterations  which  affect 
these  properties.  The  organic  sensibility  and  the  insen- 
sible contractility  especially  are  raised  in  it  in  a remark- 
able degree  in  the  plica  polonica ; now  in  order  to  have 
the  degree  of  energy  which  they  then  do,  they  must  have 
existed  there  in  a natural  state.  It  is  these  two  proper- 
ties, that,  the  sympathies  of  which  we  have  spoken, 


PILOUS  SYSTEM. 


403 


put  into  action.  The  organic  contractility  is  nothing  in 
the  hairs. 

Yet  we  cannot  deny  that  in  the  natural  state,  these 
organs  are,  next  to  the  epidermis  and  the  nails,  those  in 
which  life  is  the  least  active,  those  which  have  the  least 
numerous  relations  with  the  other  organs.  Whilst  every 
thing  is  destroyed  in  most  of  the  other  systems  by  dis- 
eases, this  is  most  often  unaffected  by  them  ; it  grows  as 
usual,  and  appears  to  be  in  no  wise  disturbed  ; it  has  then 
a manner  of  being,  of  existing,  wholly  different  from  the 
others. 

In  general,  the  external  productions  of  animals,  as  the 
feathers,  the  hair,  the  scales,  &c.  seem  to  form  a separate 
class  of  organs,  foreign  to  the  life  of  the  internal  organs , 
it  is  almost  like  the  different  species  of  mosses  that  grow 
upon  trees,  without  making  essentially  a part  of  them. 


ARTICLE  FOURTH. 


DEVELOPMENT  OF  THE  PILOUS  SYSTEM. 


I.  State  of  this  System  in  the  First  *^ge.. 

In  the  first  months  of  the  foetus  there  are  no  hairs  on 
the  skin  which  is  then  gelatinous.  It  is  when  the  fibres 
of  the  dermoid  texture  are  formed,  that  there  begins  to 
appear  on  the  head  a light  down,  an  indication  of  the 
hairs  which  are  afterwards  to  arise.  This  down  is  whitish 
and  concealed  by  that  fatty  and  unctuous  substance,  which 


404 


PILOUS  SYSTEM. 


we  have  said  is  deposited  on  the  external  surface  of  the 
skin  at  this  age.  Soon  this  down,  which  appears  to  be 
but  the  external  covering  of  the  hairs,  which  is  then  of 
extreme  tenuity,  begins  to  be  coloured  black  or  flaxen, 
according  to  the  tint  that  is  afterwards  to  predominate ; 
it  is  the  internal  substance  that  forms  it.  The  colour  re- 
mains faint  until  after  birth.  At  this  period  the  hairs  are 
often  more  than  half  an  inch  long.  Upon  all  the  rest  of 
the  body  there  is  only  the  down,  the  precursor  of  the 
hairs  ; the  face  especially  has  much  of  it.  The  hairs  of 
the  head  are  then  in  advance  ,at  one  period  of  the  other 
hairs,  in  their  growth. 

After  birth  the  hairs  grow  much  more  rapidly  than  be- 
fore. It  is  precisely  the  reverse  of  most  of  the  other 
parts,  whose  growth  is  more  rapid  in  the  womb  of  the 
mother.  During  the  whole  of  youth  this  system  has  a 
tint  less  deep,  than  it  is  afterwards  to  have.  The  flaxen 
becomes  nearer  the  chesnut,  and  this  nearer  black,  and 
the  first  tints  of  the  bright  red  grow  many  degrees  darker 
tovvards  the  period  from  the  twenty-sixth  to  the  thirtieth 
year.  The  light  tints  are  to  the  pilous  system  in  youth, 
what  the  imperfectly  developed  forms  are  to  the  muscu- 
lar, cellular,  &c.  Oftentimes  that  which  is  to  be  after- 
wards flaxen,  approaches  a whitish  tint,  which  is  owing 
only  to  the  nature  of  the  internal  substance,  and  not  to  its 
absence  in  old  age.  Thus  the  white  of  the  Albinoes  de- 
pends also  upon  the  peculiar  Species  of  this  internal  sub- 
stance. Many  hairs  are  wanting  upon  the  body  of  the 
young  man. 

II.  State  of  the  Pilous  System  in  the  following  Jiges. 

At  puberty  there  is  a remarkable  revolution  in  this 
system  which  becomes  almost  double.  The  hairs  of  the 
genital  parts  are  formed ; the  beard  which  is,  as  I have 
said,  the  characteristic  attribute  of  the  male  in  the  human 
species,  is  also  then  developed.  We  might  say  that  there 


PILOUS  SYSTEM. 


405 


was  the  same  relation  between  the  hairs  of  the  neigh- 
bourhood of  the  testicles  and  those  of  the  beard,  as  be- 
tween the  testicles  themselves  and  the  organs  of  the 
voice,  between  the  womb  and  the  mammae.  The  beard 
is,  in  this  respect,  the  external  sign  of  virility.  Some 
time  before  it  comes  out,  we  see  under  the  skin  the  sac 
which  contains  the  origin  of  the  hairs  ; it  is  already  very 
evidently  formed,  and  permits  the  principle  of  the  organ  ' 
to  be  seen  which  it  is  to  contain,  as  I have  oftentimes  as- 
certained ; thus  the  sac  of  the  tooth  exists  a long  time  be- 
fore the  tooth  is  cut. 

At  the  same  time  the  hairs  of  the  axilla  grow  also ; 
those  of  the  trunk  and  extremities,  which  were  then  al- 
most in  a state  of  down,  become  larger,  assume  a deter- 
minate colour,  and  increase  even  much  in  number. 

Why  does  puberty  occasion  this  general  growth  in  the 
pilous  system  ? This  is  asking  the  reason  of  all  the  other 
phenomena  which  appear  at  this  period.  I would  only 
observe  that  the  hairs  of  the  head,  the  eyebrows,  the  eye- 
lashes and  the  hairs  at  the  openings  of  the  body,  are  those 
which  are  the  least  affected  by  this  revolution.  Besides, 
this  growth  is  gradual ; it  requires  at  least  two  or  three 
years  for  the  beard  to  become  what  it  is  always  to  be. 

In  the  following  ages  the  hairs  undergo  but  few  changes ; 
they  grow  in  proportion  as  they  are  cut  in  different  parts, 
and  are  the  seat  of  a constant  external  work  ; now,  observe 
that  this  work  is  more  prompt,  and  the  growth  of  the 
hairs  consequently  more  rapid,  in  summer  in  which  the 
cutaneous  organ  is  especially  in  action,  than  in  winter  in 
which  it  is  contracted  ; an  additional  proof  of  the  real 
vitality  of  the  organic  forces  of  the  internal  substance  of 
the  hairs. 

III.  State  of  the  Pilous  System  in  Old  Age. 

Towards  the  end  of  life,  the  pilous  system  is  affected 
by  the  general  obliteration  which  takes  place  in  almost  all 


406 


PILOUS  SYSTEM. 


the  external  vefasels ; it  ceases  at  first  to  receive  the  col- 
ouring substance.  ■ The  internal  substance  dies,  the  epi- 
dermoid covering  remains  alone  ; the  hairs  become  white. 
The  hairs  of  the  head  appear  tlie  first,  and  are  the  first  to 
die.  The  beard,  the  hairs  of  the  genital  parts  and  then 
those  of  all  the  parts  of  the  body  afterwards  die.  Be- 
sides, there  is  a great  vai'iety  among  men  as  it  respects 
tlie  period  in  which  the  hairs  whiten  ; in  some,  this  phe- 
nomenon begins  about  the  thirtieth  year,  and  even  sooner, 
in  others  it  is  towards  the  fortieth,  fiftieth  or  sixtieth.  A 
thousand  causes  arising  from  the  passions  of  the  mind, 
from  diseases,  aliments,  &c.  can  have  an  influence  in  so- 
ciety upon  this  premature  death,  so  common  in  many 
men,  but  which  does  not  take  place  in  animals,  who  are 
not  exposed  from  their  kind  of  life,  to  the  same  revolu- 
tions, until  the  last  years. 

The  hairs,  after  remaining  white  for  a longer  or  shorter 
time,  finally  fall  out;  then  the  sac  which  covered  the 
origin  of  them  flattens  down  and  entirely  disappears.  I 
have  examined  many  bald  heads ; the  skin  of  the  cranium 
was  perfectly  smooth  on  its  internal  surface,  though  it 
had  been  separated  from  tbe  cellular  texture.  No  trace 
is  discoverable  there  of  the  innumerable  appendices  which 
the  canals  form,  after  the  hairs  they  contain  have  been 
drawn  inwards.  I have  also  dissected  a man  who  after  a 
putrid  fever  had  become  almost  entirely  bald.  There 
were  all  these  little  canals  entire,  and  in  the  bottom  of 
them  could  already  be  seen  the  rudiments  of  new  hairs. 
There  is  then  this  diflerence  between  the  falling  out  of 
the  hairs  of  old  people,  and  that  which  is  the  consequence 
of  diseases,  that  every  thing  dies  in  the  first,  because  the 
vessels  which  go  to  the  root  cease  to  transmit  fluids  to  it ; 
whereas  in  the  second  case  the  hair  alone  falls  out,  and 
its  sac  remains. 

It  is  a pretty  generally  received  opinion  that  the  hair, 
the  nails  and  the  epidermis  continue  to  grow  after  death. 


PILOUS  SYSTEM. 


407 


We  have,  I think,  but  few  data  respecting  this  singular 
phenomenon.  I am  however  certain  that  I observed  a 
real  elongation  of  the  hairs  of  a chin  of  a head  that  had 
been  carefully  shaved,  and  which  I macerated  eight  days 
in  a cellar.  An  attendant  of  the  dissecting  room,  who 
prepares  many  heads  for  the  bones,  informed  me  that  he 
had  often  made  the  same  remark,  when  putrefaction  is 
prevented  for  some  time.  What  is  certain  also  is,  that  the 
growth  of  the  beard  is  not  in  the  direct  ratio  of  the  vital 
forces  ; in  the  diseases  which  affect  these  forces  with 
a general  prostration,  it  grows  as  much  as  in  those  in 
which  there  is  a general  exaltation  of  these  forces.  W^e 
remark  this  in  hospitals  where  at  the  side  of  an  inflam- 
matory fever,  there  is  often  found  a putrid  or  slow  nerv- 
ous one.  Besides,  why  should  there  not  be  sufEcient 
tonic  forces  left  in  the  hairs  to  grow  some  time  after 
general  death,  as  there  is  in  the  lymphatics  to  absorb,  &c.  ? 

The  diflerent  phenomena  which  the  hair,  the  epider- 
mis, the  skin,  and  in  general  all  the  external  organs  ex- 
perience in  the  successive  ages,  are  wholly  owing,  like 
those  of  the  internal  organs,  to  the  laws  of  nutrition,  and 
not  to  the  action  of  surrounding  bodies.  This  is  an  essen- 
tial diflference  between  organic  and  inorganic  bodies.  The 
latter  are  gradually  altered  in  two  ways  by  the  contact  of 
external  bodies  which  act  upon  them,  1st,  mechanically 
by  friction,  tearing,  &c.  &c.  ; 2d,  chemically,  by  combin- 
ing with  them,  as  for  example,  the  air  whose  different 
principles  undergo  many  combinations  which  change  its 
nature  and  that  of  the  bodies  with  which  it  is  in  contact. 
In  this  respect  all  inorganic  bodies  grow  old.  At  the  end 
of  some  time,  they  have  no  longer  the  exterior  which 
characterized  them  in  the  beginning.  Observe  monuments, 
pictures,  engravings,  earths,  metals,  stones,  &c.  &c.  every 
thing  which  in  the  arts,  commerce,  sciences,  in  the  uses  of 
life  or  in  the  phenomena  of  nature  is  formed  of  any  inert 
bodies,  whether  these  bodies  have  never  lived,  or  having 


40S 


PILOUS  SYSTEM. 


lived,  have  not  been  able  to  preserve  themselves  after  death, 
as  the  solid  portions  of  vegetables,  the  bones,  the  horns,  the 
hair  of  animals,  &c.  every  thing  finally  has  the  indelible 
stamp  of  time  ; every  thing  grows  old  ; every  thing  loses 
its  freshness,  every  thing  changes  on  the  exterior  of  inert, 
as  well  as  on  that  of  organic  bodies  ; but  as  in  the  first  sur- 
rounding bodies  alone  have  acted,  the  internal  partis  still 
young,  whilst  the  external  is  old,  if  I may  be  allowed  to 
use  two  very  improper  words.  Thus  the  rock  whose  sur- 
face is  blackened  by  the  lapse  of  years,  is  the  same  in  the 
interior  as  when  it  was  created.  On  the  contrary  in  ani- 
mals and  vegetables,  the  internal  organs  are  worn  out,  as 
well  as  the  exterior.  Time  is  marked  upon  the  viscera,  as 
well  as  upon  the  forehead  of  the  aged.  Surrounding 
bodies  act  upon  us,  wear  out  life,  if  we  may  so  say  ; but 
it  is  as  stimuli  that  they  exert  their  action ; it  is  by  ex» 
hausting  the  sensibility  and  contractility,  and  not  by  com- 
bination, mechanical  contact  or  friction.  Language  ought 
to  express  this  difference.  We  do  not  use  the  term 
young  when  viewing  the  exterior  of  a new  building,  a 
new  garment,  or  a picture  recently  painted  ; why  do  we 
say  an  old  monument,  an  old  piece  of  cloth,  &c.  ? if  it  is 
a metaphor,  very  well ; but  this  word  cannot  express  a 
state  analogous  in  its  nature,  to  that  of  an  old  animal,  an 
old  plant,  &c. 

IV.  Preternatural  Development. 

There  are  three  principal  cases  in  which  the  hairs  are 
preternaturally  developed  in  the  economy. 

1st.  Sometimes  they  are  formed  on  the  internal  sur- 
face of  the  mucous  membranes ; they  have  been  seen  in 
the  bladder,  the  stomach  and  the  intestines  ; many  authors 
have  given  cases  of  them.  I have  found  them  upon  the 
calculi  of  the  kidney.  I have  seen  in  the  gall-bladder  at 
one  time  a dozen  of  nearly  an  inch  in  length,  and  which 
were  evidently  implanted  in  its  surface. 


PILOUS  SYSTEM. 


409 


2d.  There  is  often  seen  on  the  skin  preternatural  col- 
lections of  them,  which  are  usually  a defect  from  birth. 
These  collections  are  particularly  observed  upon  some  of 
those  productions  or  irregular  excrescences,  that  are  called 
naevi  materni.  There  was  exhibited  at  Paris,  six  years 
since,  an  unfortunate  person,  who  had  from  his  birth  his 
face  covered  with  hairs  almost  like  those  of  a wild  boar ; 
and  to  whom  there  came  on  at  the  age  of  thirty-six  years, 
that  particular  species  of  elephantiasis,  in  which  the  skin  of 
the  face  increased  in  size,  exhibits,  if  we  may  so  say,  the 
features  of  the  lion,  a species  which  I have  since  had 
occasion  to  observe  upon  a natural  skin.  This  double 
circumstance  gave  to  the  face  of  this  man  an  air  of  fero- 
city which  it  is  impossible  to  describe.  Many  of  the 
stories  circulated  by  the  vulgar  concerning  men  with  the 
heads  of  wild  boars,  bears,  &c.  are  nothing  but  these  nsevi 
in  the  face,  with  a growth  of  hair  upon  them. 

3d.  Hairs  are  often  preternaturally  developed  in  cysts, 
in  those  of  the  ovaria  especially.  A great  many  instances 
have  been  related.  Haller  in  particular  has  collected 
many  ; I have  seen  two.  The  following  is  what  they  ex- 
hibit ; a considerable  large  sac  contained  many  very  dis- 
tinct small  balls,  analogous  to  those  of  the  dung  of  sheep, 
formed  by  a fat,  unctuous,  whitish  substance,  very  differ- 
ent in  its  appearance  from  ordinary  fat.  On  the  internal 
surface  of  this  sac  were  implanted  many  hairs,  which  the 
least  force  could  remove,  because  they  hardly  penetrated 
below  the  surface.  These  hairs  were  black.  Many 
already  detached  were  found  crossed  in  different  direc- 
tions, in  the  small  balls  of  fatty  matter,  which  was  like 
spermaceti  ; for  it  very  much  resembled  the  substance 
into  which  the  fat  is  changed  by  maceration. 


END  or  THE  LAST  VOLUME. 


VOL.  III. 


52 


■ -v-  ■ m;v 


* .*'.'■1 


('  -l>  '<  ■ ' ■** 


.-  - I " - ; ,.  ■ 

, I I'V  :':'.i  4'-‘!;  ^V.'  I "■,;  / ” ;"t' 

',  V ,-*sj  '*'  ''  ' 


V,'; 


AJVALTTICAL  TABLE  OF  COJ^TEJ^TS. 


VOLUME  FIRST. 

PAGE. 

Preface  by  the  Translator.  5 

Preface  by  the  Author.  ih. 

GENERAL  OBSERVATIONS. 

Of  Animate  and  Inanimate  Beings. — Of  their  Laws. — Of 
the  Sciences  which  treat  of  their  Phenomena.  9 

I.  General  Remarks  upon  the  Physiological  and  Physical  Sciences. 

The  differences  between  these  sciences  are  derived  from 
the  properties  which  preside  over  the  phenomena.— 

The  necessity  of  always  connecting  the  second  with  the 
first. — Periods  at  which  this  progress  commenced  in 
the  physical  sciences.  False  applications  made  to  the 
physiological  sciences. — The  necessity  of  following  in 
these  the  same  course  as  in  the  others.  9 

II.  Of  the  Vital  Properties,  and  their  influence  upon  the  pheno- 

mena of  the  Physiological  and  Physical  Sciences. 

Vital  properties  considered  in  the  series  of  living  beings. 

— Of  those  which  animate  plants. — Consequences  in  re- 
gard to  their  diseases. — Of  those  which  belong  to  ani- 
mals.— Consequences  in  regard  to  their  diseases. — Ex- 
amination of  each  vital  property  under  the  relation  of 
the  diseases  over  which  it  presides. — Necessity  of  re- 
ferring to  these  properties  the  action  of  medicines. 

— Uncertainty  of  the  Materia  Medica. — Each  vital  pro- 
perty has  a particular  class  of  medicines  which  act  upon 
it. — Proofs. — Inconveniences  of  describing  morbid  phe- 
nomena and  those  of  medicines  in  too  general  a man- 
ner.— Consequences  of  the  preceding  remarks.  13 


412 


ANALYTICAL  TABLE 


PAGE 

III.  Characters  of  the  Vital  Properties,  compared  with  the  charac- 

ters of  the  Physical  Properties. 

Extreme  variableness  of  the  first,  invariableness  of  the 
second. — Consequences  of  this  principle  as  it  regards 
the  phenomena. — There  can  only  be  diseases  where 
there  are  vital  properties. — Why. — The  progress  of 
the  physiological  and  physical  sciences  wholly  different 
in  this  respect. — Differences  between  animate  and  in- 
animate solids  and  fluids. — The  vital  propertie's  become 
exhausted,  the  physical  do  not — Consequences. — The 
latter  are  inherent  in  matter,  the  others  are  not. — 
General  remarks  upon  the  enumeration  of  the  differ- 
ences of  animate  and  inanimate  bodies. — Particular  re- 
mark relative  to  sympathies. — Their  general  pheno- 
mena. 23 

IV.  Of  the  Vital  Properties  and  their  Phenomena  considered  in 

relation  to  the  Solids  and  the  Fluids. 

Division  of  the  fluids  into  those  of  composition  and 
those  of  decomposition. — The  vital  properties  are 
seated  essentially  in  the  solids. — These  are  the  seat  of 
almost  all  the  morbid  symptoms. — The  fluids  however 
may  be  affected. — Different  attributes  of  the  fluids  of 
composition  and  of  those  of  decomposition  in  diseases. 

— How  the  alterations  of  the  first  may  take  place. — Of 
those  of  the  second. — Of  the  cases  in  which  the  solids 
and  the  fluids  are  primarily  affected. — Division  of  dis- 
eases in  this  view. — The  question  must  necessarily  be 
considered  in  many  points  of  view. — What  is  true  on 
one  side  is  not  so  on  another. — Of  the  vitality  of  the 
fluids. — What  it  is. — Their  alterations  affect  their  vi- 
tality.— New  proofs  of  these  alterations. — How  the 
fluids  are  assimilated  and  altered.  29 

V.  Of  the  Properties  Independent  of  Life. 

Properties  of  texture. — Of  contractility  by  the  horny 
hardening. — Of  the  agents  which  put  it  into  action. — 

It  is  of  two  kinds. — Characters  of  each. — Their  differ- 
ences.— Almost  all  the  solids  undergo  the  horny  hard- 
ening.— Condition  which  it  requires. — Of  the  horny 
hardening  during  life  and  after  death. — Difference  of 
this  contractility  lioin  the  others. — General  remarks.  38 


OF  CONTENTS. 


413 


PAGE 

Tl.  General  Observations  upon  the  Organization  of  Animals. 

Of  the  simple  systems. — Necessity  of  considering  them  ab- 
stractedly.— Their  difference  of  forms. — Their  variety 
of  organization,  1st,  in  the  peculiar  texture  ; 2d,  in  the 
common  parts. — Manner  of  knowing  these  differences. 

— Differences  of  the  vital  properties  and  of  texture. — 

Of  the  peculiar  life. — It  cannot  be  understood  of  the 
compound  organs,  but  of  the  simple  systems. — Exam- 
ples which  prove  this  assertion  in  the  different  organs.  44 

VII.  Consequences  of  the  preceding  Principles  relative  to  Diseases- 

Each  texture  can  be  separately  affected  in  an  organ. — 

This  even  almost  always  happens. — Various  proofs  of 
this  assertion. — Observations  upon  different  diseases. 

— Sympathies  do  not  take  place  in  an  organ  as  a whole, 
but  in  some  one  texture  of  this  organ. — Why. — Of  sym- 
pathetic fevers. — The  different  inflammations  vary  in 
each  texture. — Phenomena  of  the  different  kinds  of 
virus  variable  from  the  same  cause. — Yet  Jhe  different 
textures  of  the  same  organ  have  a certain  dependance 
upon  each  other. — Proofs. — Diseases  chronic  and  acute. 

— Differences  of  diseases  in  each  simple  system. — Two 
classes  of  sytnptoms  in  the  local  affections. — Their  dif- 
ference.— Varieties  of  the  pain,  heat,  &c.  according  to 
the  systems. — What  should  be  understood  by  acute  and 
chronic  affections  in  the  simple  systems. — Influence  of 
these  considerations  upon  morbid  anatomy. — Defects  of 
the  old  divisions. — New  manner  of  considering  morbid 
anatomy.  49 

VIII.  Remarks  upon  the  Classification  of  the  Functions. 

Table  of  this  classification.  60 


SYSTEMS  COMMON  TO  ALL  THE  APPARATUS. 
General  Observations. 

Division  of  the  systems. — Systems  common  to  all  the  ap- 
paratus.— Their  characters. — They  form  the  nutiit  ve 
paranehyma  of  the  organs. — Remarks  upon  nutrition. — 
Diversity  of  the  nutritive  substances.  77 


414 


ANALYTICAL  TABLE 


CELLULAR  SYSTEM. 

PAGE 

General  Remarks. — Division.  87 


ARTICLE  FIRST. 

OF  THE  CELLULAR  SYSTEM  CONSIDERED  IN  RELATION  TO  THE 
ORGANS. 

I.  Of  the  Cellular  System  exterior  to  each  Organ. 

Division  of  the  organs  in  relation  to  the  neighbouring 
texture.  88 

Of  the  Cellular  System  which  adheres  only  to  one  side  of  the 
organs. 

Sub-cutaneous  cellular  texture. — Arrangement  of  this  tex- 
ture, 1st,  upon  the  median  line ; 2d,  in  the  different 
regions  of  the  bodj'. — Varieties  of  density  and  laxity. 

Uses  of  the  sub-cutaneous  texture. — Its  fluids.  88 

Sub-mucous  cellular  texture. — Difference  of  this  texture 
from  the  preceding. — The  density  of  that. — Conse- 
quences. 

Sub-serous  cellular  texture. — It  is  in  general  loose  and 
abundant. — Why. — Place  where  it  is  dense.  92 

Cellular  texture  exterior  to  the  arteries. — Its  peculiar  nature 
is  analogous  to  that  of  the  sub-mucous  texture. — Its  re- 
lations with  the  arterial  fibres. 

Cellular  texture  exterior  to  the  veins. — It  is  analogous  to  the 
preceding,  only  less  thick. — Remarks. 

Cellular  texture  exterior  to  the  excretory  ducts. — The  same 
structure  and  arrangement  as  in  the  preceding.  96 

Of  the  cellular  system  considered  in  relation  to  the  organs 
that  it  surrounds  on  all  sides. — Cellular  atmosphere. — 
Fluids  of  this  atmosphere. — Insulation  of  the  vitality  of 
the  organs. — Of  this  atmosphere  considered  as  a means 
for  the  propagation  of  diseases. — It  favours  the  mo- 
tion of  the  parts.  96 

II.  Of  the  Internal  Cellular  System  of  each  Organ. 

Arrangement  of  this  texture. — Us  uses. — Us  different  pro- 
portions. 102 


OF  CONTENTS. 


415 


ARTICLE  SECOND. 


OP  THE  CELLULAR  SYSTEM  CONSIDERED  INDEPENDENTLY  OF  THE 
ORGANS. 

PAGE 

I.  Of  the  Cellular  System  of  the  Head. 

Cellular  texture  of  the  cranium. — It  is  almost  nothing  within. 

— Its  communications. — Consequences  of  these  com- 
munications.— It  is  more  abundant  without. 

Cellular  texture  of  the  face. — It  is  very  abundant. — Its 
uses. — Its  communications,  &c.  104 

II.  Of  the  Cellular  System  of  the  Trunk. 

Vertebral  cellular  texture. — It  is  not  abundant  in  the  cavity 
of  the  canal. — On  the  exterior,  there  is  but  little  be- 
hind, and  more  in  front. — Consequences. 

Cervical  cellular  texture. — It  is  abundant. — Its  communica- 
tions.— C onsequences. 

Pectoral  cellular  texture. — It  is  found  especially  upon  the 
median  line. — Its  communications. — External  texture. 

Abdominal  cellular  texture. — Of  the  parts  in  which  it  is 
most  abundant. — Its  communications. 

Cellular  texture  of  the  pelvis. — It  is  very  abundant. — Why. 

— Consequences. — Its  communications.  108 

III.  Of  the  Cellular  System  of  the  Extremities. 

Its  different  proportions  in  the  superior  and  the  inferior.  112 


ARTICLE  THIRD. 

OF  THE  FORMS  OF  THE  CELLULAR  SYSTEM,  AND  THE  FLUIDS  IT 
CONTAINS. 

I.  Of  the  Cells. 

Their  form. — Their  capacity. — Their  communication  — 
Experiments. — Of  the  cellular  permeability. — In  what 
sense  it  should  be  understood.  114 

II.  Of  the  Serum  of  the  Cellular  Membrane. 

Proof  of  its  existence. — Its  evaporation. — It  varies  in 
the  different  regions. — Method  of  ascertaining  the  pro- 


416 


ANALYTICAL  TABLE 


PASE 

portions  of  it. — Experiments. — Nature  of  this  fluid. — 
Experiments.  117 

III.  Of  (he  Cellular  Fat. 

J^atural  proportions  of  the  fat. — Varieties  of  its  propor- 
tions according  to  the  regions,  organs,  s3'stenis,  &c  — Its 
peculiar  arrangement  in  childhood. — Varieties  accord- 
ing to  the  other  ages.  ’ 119 

Unnatural  proportions  of  fat. — Its  preternatural  abundance 
indicates  weakness. — Different  proofs. — Of  the  causes 
of  the  diminution  of  fat. — Remark  upon  this  diminu- 
tion. 121 

Different  states  of  the  fat. — Its  degree  of  fluidity  is  not 
during  life  in  proportion  to  temperature. — Its  consist- 
ence in  young  animals. — Consequences. — Its  alterations 
by  age,  diseases,  &c.  125 

Exhalation  of  fat. — Different  opinions. — The  fat  is  ex- 
haled.— Proofs. — Nature  of  this  fluid. — Relation  of  its 
uses  with  the  places  where  it  exists  and  with  those  in 
which  it  is  wanting.  127 


ARTICLE  FOURTH. 

OK.GAXIZATION  OF  THE  CELLUL.AR  SYSTEM. 

I.  Texture  peculiar  to  the  organization  of  the  Cellular  System. 

Filaments  and  layers  from  which  it  results. — Method  of 
seeing  them  to  advantage. — Their  nature. — Essential 
ditference  in  the  cellular  organization. — There  are  two 
species  of  cellular  texture.  129 

Composition  of  the  cellular  texture. — Experiments  upon 
this  texture. — Action  of  the  air,  water,  caloric  and  the 
gastric  juices. — Experiments. — Of  the  gases  sometimes 
extricated  in  the  cellular  texture.  132 

II.  Parts  common  to  the  Organization  of  the  Cellular  Texture. 

Blood  vessels. — The  inaccuracy  of  injections  in  demon- 
strating them. 

Exhalants. — Of  the  cellular  exhalations. — Proofs  and  phe- 
nomena of  these  exhalations. 

Absorbents. — Cellular  absorptions. — Proofs. — The  cellular 
texture  is  not  wholly  formed  of  absorbents. 

JVerves. 


136 


OF  CONTENTS. 


417 


ARTICLE  FIFTH. 

PROPERTIES  OF  THE  CELLULAR  SYSTEM. 

I.  Properties  of  Texture. 

PAGE 

Exlcnsibility. — Examples  of  the  different  distensions. — 
Distinctive  character  of  the  cellular  extensibility. — Its 
phenomena. — It  becomes  nothing  in  inflammation,  chro- 
nic engorgements,  &c. 

Contractility. — Different  examples  of  this  property  brought 
into  action. — Its  varieties  according  to  the  ages. — Gene- 
ral remarks.  140 

II.  Vital  Properties. 

The  animal  ones  are  inconsiderable. — The  organic  are 
greater,  except  sensible  contractility,  which  however 
exists  to  a certain  extent. 

Sympathies. — It  is  necessary  to  distinguish  them  from  the 
phenomena  of  juxta-position. — V'^arious  examples. — 
General  observations. — Vital  properties  put  in  action 
by  the  sympathies. 

Character  of  the  vital  properties. — The  vital  activity  is  very 
considerable  in  the  cellular  texture. — Various  proofs. — 
Remarks  upon  the  species. — Difference  of  vitality  in 
the  two  species  of  cellular  texture.  143 

III.  Properties  of  Re-production. 

Infuence  of  the  cellular  texture  upon  the  formation  of  cica- 
trices.— Division  of  the  periods  of  the  cicatrices. 

First  period. — Inflammation. — How  it  takes  place. — Its  ad- 
vantages. 

Second  period. — Fleshy  granulations. — Experiments. — 
Provisional  membrane  of  the  cicatrices. — Its  uses. — 
General  phenomena  of  the  interna!  cicatrices. — Cellu- 
lar nature  of  this  membrane  and  of  the  granulations. 

— Different  opinions. 

Third  period. — Suppuration. — What  corresponds  to  it  in 
the  internal  cicatrices. — Analogy  of  these  cicatrices 
with  the  external. 

Fourth  period. — Contraction  of  the  fleshy  granulat’ons. — 
Adhesions. — Consequences  of  the  preceding  principles, 

— Of  union  by  the  first  intention. 

VOL.  III.  .53 


148 


418 


ANALYTICAL  TABLE 


PAGE 

Injluence  of  the  cellular  texture  in  the  formation  of  tumours. 

— Cellular  nature  of  all  tumours  which  grow  aud  in- 
crease.— Proofs. — Mode  of  development  of  these  tu- 
mours.— How'  they  differ  from  various  engorgements, 
acute  and  chronic.  157 

Influence  of  the  cellular  texture  in  the  formation  of  cysts. — 
What  is  a cyst. — Its  analogy  with  the  serous  surfaces. 

— Its  cellular  structure. — Mode  of  its  development.  160 


ARTICLE  SIXTH. 

DEV'ELOPMEKT  OF  THE  CELLULAR  TEXTURE. 

I.  State  of  the  Cellular  System  in  the  First  Jlge. 

Mucous  mass  represented  by  the  cellular  texffire  of  the 

foetus. — Superabundance  of  fluid. — This  is  then  the 
cellular  fluid. — Difficulty  of  emphysema  in  the  foetus. — 
State  of  the  cellular  texture  in  infancy  and  youth. — Its 
vital  energy. — Consequences.  164 

II.  State  of  the  Cellular  System  in  the  After  Ages. 
Arrangement  of  the  cellular  texture  in  the  adult. — 

Differences  arising  f rom  sex. — Degeneracy  of  this  tex- 
ture in  old  age. — Withering  that  it  experiences. — Con- 
sequences. 167 


NERVOUS  SYSTEM  OF  ANIMAL  LIFE. 

Division  of  the  nerves  into  two  systems. — Differences  of 
these  two  systems. — General  arrangement  of  that  of 
animal  life. — Its  symmetry. — Relation  of  size  between 
the  nerves  and  the  brain.  169 


ARTICLE  FIRST. 

EXTERNAL  FORMS  OF  THE  NERVOUS  SYSTEM  OF  ANIMAL  LIFE. 

I.  Origin  of  the  Cerebral  Nerves. 

In  what  sense  this  origin  must  be  understood. — It  takes 
place,  1st,  in  the  brain;  2d,  in  the  tuber  annulare  and 


OF  CONTENTS. 


419 


PAGE 

its  dependancies ; 3d,  in  the  spinal  marrow. — Manner  of 
this  triple  origin. — Of  the  crossing  of  the  nerves. — 
Phenomena  of  paralysis  in  regard  to  this. — Peculiar 
arrangement  of  the  cerebral  membranes  at  the  origin 
of  the  nerves. — Extent,  direction  and  form  of  the  nerves 
at  this  origin.  171 

II.  Course  of  the  Cerebral  JVerves. 

Communications  of  the  cerebral  nerves  at  their  eocit  from  their 
osseous  cavity. — There  are  none  between  the  nerves  of 
the  brain  properly  called. — The  communications  begin 
in  those  of  the  tuber  annulare. — They  are  very  nume- 
rous in  those  of  the  spinal  marrow. — Arrangement  of 
the  plexuses  which  result  from  them. — Consequences 
as  it  regards  descriptive  neurology. 

Internal  communications  of  the  nervous  cords. — Manner  of 
these  communications. — Internal  plexus  to  each  nerve. 

— Consequences. — Difference  from  anastomoses. 

Nervous  Trunks. — Their  course. — Their  form.— Their 
length,  &c. 

Nervous  branches.,  smaller  branches,  ramifications,  fyc. — 
Mode  of  origin. — Length. — Course,  &c.  , 176 

III.  Termination  of  the  Nerves. 

What  is  to  be  understood  by  it. — Triple  mode  of  termina- 
tion. 

Anastomoses  with  the  same  system. — What  is  to  be  under- 
stood by  anastomoses. — They  are  rare  in  this  system. 

— They  can  be  referred  to  three  classes. 

Anastomoses  with  the  system  of  organic  life. — Termination 
in  the  organs. — Manner  of  this  termination. — Division 
of  the  organs  in  this  respect.  182 


ARTICLE  SECOND. 


ORGANIZATION  OF  THE  NERVOUS  SYSTEM  OF  ANIMAL  LIFE. 

I.  Texture  peculiar  to  this  Organization. 

Arrangement  of  the  nervous  cords. — Their  varieties. — 
Each  nerve  has  its  peculiar  organization. — Of  the  struc- 
ture of  the  nervous  filaments. 


420 


ANALYTICAL  TABLE 


PAGE 

Of  the  nervous  coat  and  its  origin. — How  this  origin  may  be 
seen. — Its  triple  arrangement  at  the  brain,  the  tuber 
annulare  and  the  spina!  marrow. — Particular  arrange- 
ment of  the  optic  nerve. — Remarks  upon  the  pia  mater. 

— Course  of  the  nervous  coat.  185 

dclio7i  of  certain  substances  vpon  the  nervous  coat  ; its  resist- 
ance, ij-c. — Action  oi'  the  acids,  water,  caloric,  and  the 
alkaiie.s. — Resistance  of  the  nervous  coat. 

Medullary  substance ; its  origin,  arrangement  and  propor- 
tions. 

Comparison  between  the  medullary  substance  of  the  brain  and 
the  nerves. — Effect  of  desiccation  upon  each. — Putrefac- 
tion and  its  phenomena. — Absence  of  the  horny  harden- 
ing in  both. — Action  of  water  upon  both. — Action  of 
the  acids,  the  alkaTies,  neutral  salts  and  the  digestive 
juices. — Difference  of  the  nervous  pulp  in  each  part.  190 

II.  Parts  common  to  the  Organization  of  the  JVervous  System  of 
Animal  Life. 

Cellular  texture. — It  is  wanting  in  the  nerves,  in  the  cra- 
nium and  the  spine.  Elsewhere  it  is  found  between 
their  filaments  and  cords. — Cellular  fat. 

Blood  vessels. — Their  arrangement. — Remarks  upon  the 
veins. — Of  the  blood. — Of  the  nerves. — Action  of  this 
fluid  upon  them. 

Exhalants  and  Absorbents. — Examination  of  the  opinion 
upon  the  exhalation  of  the  nervous  coat. — Different 
observations. 

Nerves.  199 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  NERVOUS  SYSTEM  OF  ANIMAL  LIFE. 

I.  Properties  of  Texture. 

They  are  but  very  slightly  marked. — Remarks  upon  the 
nervous  distensions.  204 

II.  Vital  Properties. — Properties  of  Animal  Life. 

Animal  sensibility  inherent  in  the  nerves. — Various  experi- 
ments upon  this  sensibility. — Remarks  upon  that  of 
the  brain. — Phenomena  of  the  experiments  upon  the 
nerves. — Character  of  the  animal  nervous  sensibility. 


OF  CONTENTS. 


421 


I'AGE 

— Of  neuralg-ias. — Another  character  of  this  sensibility. 

— Experiments. — Consequences,  206 

Influence  of  the  nerves  upon  the  animal  sensibility  of  all  the 
organs. — Distinction  of  the  sensations,  in  this  respect, 
into  external  and  internal. — Subdivision  of  the  external 
into  general  and  particular. — Part  which  the  nerves 
perform  in  each. — Internal  sensations. — Uncertainty 
respecting  the  nervous  influence  in  sensations. — Difier- 
ences  between  animal  sensibility  and  contractility. — Of 
the  nervous  atmosphere. — Uncertainty  of  this  opinion.  211 
Animal  contractility. — Influence  of  the  nerves  upon  that  of 
the  other  parts. — How  the  nerves  are  the  agents  of  this 
property. — Different  opinions  upon  the  action  of  the 
nerves. — Uncertainty  of  these  opinions. — General  ob- 
servations. 

Properties  of  organic  life,  considered  in  the  nerves. — They 
are  slightly  marked. — Increase  of  the  size  of  the  nerves 
in  the  affections  of  some  parts. — Various  experiments 
and  observations. 

Influence  of  the  cerebral  nerves  upon  the  organic  properties 
of  the  other  parts. — They  are  foreign  to  these  pro- 
perties.— The}"  have  not  there  any  known  influence,  1st, 
upon  the  capillary  circulation ; 2d,  upon  exhalation; 

3d,  upon  secretion ; 4th,  upon  absorption ; 5th,  upon 
nutrition. — Diflereut  proofs  of  these  assertions. — Re- 
marks on  the  diseases  which  affect  animal  life  and 
those  which  affect  organic. — Uncertainty  of  the  term 
nervous  influence,  216 

Sympathies. — Sympathies  peculiar  to  the  nerves. — Difierent 
phenomena  of  these  sympathies. — Sympathies,  1st,  be- 
tween two  nerves  of  the  same  pair;  2d,  between  two 
nerves  of  the  same  side  ; 3d,  between  the  branches  of 
the  same  pair;  4th,  between  the  nerves  and  different 
organs. — Different  examples  of  these  sympathies.  224 
Influence  of  the  nerves  upon  the  sympathies  of  the  other 
organs — Different  opinions  upon  sympathies. — Uncer- 
tainty of  these  opinions.-  Division  of  sympathies  founded 
upon  that  of  the  vital  properties. — Different  influence 
of  the  nerves  upon  each  species  of  sj^mpathy. — Cases 
in  which  it  is  real  and  those  in  which  it  is  nothing.  226 

III.  Properties  of  Reproduction. 

Phenomena  of  nervous  cicatrizations.— -Their  analogy 
with  other  cicatrizations.  233 


422 


ANALYTICAL  TABLE 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  NERVOUS  SYSTEM  OF  ANIMAL  LIFE. 

I.  State  of  this  System  in  the  F<£tus. 

PAGE 

It  is  much  (leTeloppd.— General  remarks. — Inactivity  of 
the  brain,notwithstanding  its  development. — Its  softness. 

— Action  of  the  alkalies  upon  this  org'an. — The  cerebral 
nerves  are  developed  in  proportion. — Peculiar  phe- 
nomenon of  their  development. — This  phenomenon  is 
opposite  to  that  of  the  arteries. — Consequence  which 
results  from  it.  235 

II.  State  of  the  JVervous  System  during  Growth. 

Phenomena  at  birth. — Influence  of  the  red  blood. — Pre- 
dominance of  the  nervous  system  during  childhood. — ■ 
Consequences  relative  to  the  sensations,  motions  and 
various  affections.  240 

III.  State  of  the  JVervous  System  after  Growth. 

Phenomenon  of  puberty. — Phenomena  of  the  following 
ages.  244 

IV.  State  of  the  JVervous  System  in  Old  Jlge. 

Its  action  is  slight. — State  of  the  brain  at  this  period. — In- 
fluence of  this  state  upon  sensibility. — Phenomena  of 
sensation  and  motion  in  old  age.  244 


NERVOUS  SYSTEM  OF  ORGANIC  LIFE. 


GENERAL  REM,4RKS. 

How  this  system  should  be  understood. — The  great  sym- 
pathetic does  not  exist. — Each  ganglion  forms  an  in- 
sulated system. — This  system  belongs  to  organic  life. — 

It  exhibits  many  irregularities. — The  mode  of  describ- 
ing it.  249 


OF  CONTENTS. 


423 


ARTICLE  FIRST. 

OF  THE  GANGLIONS. 

I.  Situation,  Forms,  Relations,  4’C. 

PAGE 

Ganglions  that  are  constant. — Those  that  are  accidental.  253 

II.  Organization. 

Colour. — Difference  of  the  texture  of  the  ganglions  from 
that  of  the  brain. — Comparative  experiments. — This 
texture  is  not  fibrous. — It  differs  essentially  from  that 
of  the  nerves. — Its  organic  lesions  are  rare. — Common 
parts  of  this  texture.  255 

III.  Properties. 

The  ganglions  have  the  organic  ones. — The  animal  ap- 
pear to  he  slightly  marked  in  them. — Experiments. — 
Sympathies. — IVervous  affections  of  the  ganglions. — 

The  kind  of  pain  of  this  system. — General  remarks.  260 

IF.  Development. 

It  does  not  follow  that  of  the  hrain. — Influence  of  this 
fact  upon  the  diseases  of  childhood. — Another  difference 
between  the  ganglions  and  the  brain.  263 

V.  Remarks  upon  the  Vertebral  Ganglions. 

Their  arrangement. — Obscurity  which  they  throw  upon 
the  functions  of  this  system.  264 


ARTICLE  SECOND. 

OF  THE  NERVES  OF  ORGANIC  LIFE. 

I.  Origin. 

Manner  of  this  origin. — Method  of  seeing  it.  265 

II.  Course,  Terminatio7i,  Plexuses. 

Of  the  branches  which  go  to  the  cerebral  nerves. — Of 
those  which  go  to  the  neighbouring  ganglions. — Of 


424 


ANALYTICAL  TABLE 


PAGE 

those  which  go  the  muscles. — Of  those  which  form  the 
plexuses. — Arrangement  of  these  last. — Of  the  filaments 
which  go  from  them. — Their  double  arrangement  upon 
the  arteries.  267 

III.  Structure^  Properties^  ^-c. 

Analogy  with  the  preceding  nerves  as  to  texture. — Ani- 
mal sensibility  a}ipears  to  be  less  in  them. — Experi- 
ments.— Sympathies  of  these  nerves. — General  re- 
marks. 27 1 


VASCULAR  SYSTEM  WITH  RED  BLOOD. 


ARTICLE  FIRST. 

GENERAL  REMARKS  UPON  THE  CIRCULATION. 

1.  Division  of  the  Circulation. 

Circulation  of  red  blood. — General  organs. — Direction. 

Circulation  of  black  blood. — General  organs. — Direction. 

Difference  of  the  txsso  circulations. — Theirseparation  is  com- 
plete.— Opposition  of  the  lungs  to  all  the  parts. 

General  mechanical  phenomena  of  the  two  circulations. — Coni- 
cal form  of  the  circulatory  apparatus. — There  are  two 
cones  for  each  circulation. — The  heart  is  placed  at 
their  union  as  a double  agent  of  impulse. — Its  inequality 
in  this  respect.  273 

II.  Reflections  upon  the  General  Uses  of  the  Circulation. 

General  uses  of  the  circulation  of  the  red  blood. — It  furnishes 
the  materials  of  secretion,  exhalation,  absorption,  &c. 

— All  the  great  phenomena  of  the  economy  are  de- 
rived from  it. 

General  uses  of  the  circulation  of  black  blood. — It  repairs  the 
losses  made  by  the  preceding,  by  the  substances  which 
it  receives. — General  and  opposite  attributes  of  the  two 
sanguineous  systems.  282 


OF  CONTENTS. 


425 


ARTICLE  SECOND. 


SITUATION,  FORMS,  AND  GENERAL  ARRANGEMENT  OF  THE  VASCULAR 
SYSTEM  WITH  RED  BLOOD. 


PAGI 

Of  the  two  portions  of  this  system. — Of  their  union. — 
Position  of  the  agent  of  impulse  compared  to  the  whole 
body.  285 

I.  Origin  of  the  Arteries. 

Origin  of  the  aorta. — Peculiar  anatomical  arrangement  of 
this  origin.  287 

Origin  of  the  trunks,  branches,  smaller  branches,  fyc. — Num- 
ber of  the  arterial  divisions. — Angles  of  origin. — Pro- 
portion of  the  divisions.  288 

II.  Course  of  the  Arteries. 

Course  of  the  trunks  and  branches. — Their  position,  rela- 
tion and  direction. — Motions  which  they  communicate.  291 
Course  of  the  smaller  branches,  ramifications,  <^c. — Position. 

— Relations. — Curvatures. — These  curvatures  have  no 
influence  upon  the  motion  of  the  blood. — Proofs. — 

Uses  of  these  curvatures.  293 

Anastomoses  of  the  arteries  in  their  course. — Of  the  two 
modes  of  anastomoses. — Triple  mode  of  those  in  which 
two  equal  trunks  terminate. — Anastomoses  with  un- 
equal trunks. — General  remarks  upon  anastomoses.  296 

Forms  of  the  arteries  in  their  course. — In  what  direction  they 
are  conical. — Relation  of  capacities.  299 

III.  Termination  of  the  Arteries. 

It  takes  place  in  the  capillary  system. — Its  varieties  ac- 
cording to  the  organs.  300 


ARTICLE  THIRD. 

ORGANIZATION  OF  THE  VASCULAR  SYSTEM  WITH  RED  BLOOD. 

I.  Texture  peculiar  to  this  Organization. 

Two  principal  membranes  form  it.  301 

Peculiar  membrane  of  the  arteries. — Thickness. — Colour. — 
Experiments. — Varieties  in  the  cerebral  arteries.— 
VOL.  III.  54 


426 


ANALYTICAL  TABLE 


PAGE 

Arterial  fibres. — Arrangement  of  these  fibres  at  the 
origin  of  the  branches. — Their  nature  is  not  muscular. 
Tlieir  brittleness. — Their  resistance. — General  con- 


sequences. 302 

Action  of  different  agents  upon  the  arterial  texture. — Desic- 
cation.— Futrefaction. — Maceration. — Stewing. — Action 
of  the  acids,  the  alkalies,  &c.  308 

Membrane  common  to  the  system  with  red  blood. — Its  differ- 


ences in  the  different  regions. — Of  the  fluid  which  mois- 
tens it. — Its  relations. — Its  nature. — Its  singular  dispo- 
sition to  ossification. — Peculiar  phenomena  and  laws  of 
this  ossification. — Pathological  consequences.  311 

II.  Parts  common  to  the  Organization  of  the  Vascular  System 
with  Red  Blood. 

Blood  vessels. — Their  arrangement. — They  do  not  appear 
to  go  to  the  internal  membrane.  317 

Cellular  texture. — There  are  two  species  of  it. — Of  that 
which  unites  the  artery  to  the  neighbouring  organs. — 

Of  that  which  is  peculiar  to  it,  and  which  has  a pecu- 
liar nature. — The  arterial  fibres  are  remarkable  for 
having  none  of  this  texture  between  them. — Conse- 
quences. 318 

Exhalants  and  absorbents. — There  does  not  appear  to  be 
absorption  in  the  arteries. — Experiments.  321 

JVerves. — Of  the  cerebral  ones. — Of  the  organic  ones. — 

Their  proportion. — Their  course,  &c.  324 


ARTICLE  FOURTH. 

PROPERTIES  OF  THE  VASCULAR  SYSTEM  WTTH  RED  BLOOD. 

I.  Physical  Properties. 

Remarkable  elasticity. — Its  use. — Its  differences  from  con- 
tractility of  texture.  322 

II.  Properties  of  Texture. 

Extensibility. — 1st,  of  that  in  the  axis;  2d,  of  that  in  the 
diameter.  324 

Contractility. — Of  that  in  the  axis. — Of  that  in  the  diame- 
ter.— Its  differences  from  irritability. — Remarks  upon 
this  contractility. — Practical  consequences.  326 


OF  CONTENTS. 


427 


PAGE 

III.  Vital  Properties.  Properties  of  Animal  Life. 


Sensibility. — Experiments  upon  this  property.  329 

Contractility. — It  is  nothing.  ih. 

Properties  of  organic  life. — Sensible  organic  Contractility. — 

It  is  nothing. — Different  experiments  to  prove  it. — 
Mistakes  concerning  this  property.  330 

Insensible  organic  contractility. — How  its  influence  must  be 
understood. — Vital  activity  is  but  slightly  marked  in  the 
arteries. — General  consequences.  332 

Remarks  upon  the  causes  of  the  motion  of  the  red  blood. — 
These  causes  appear  to  be  foreign  to  the  arteries.  335 
Influence  of  the  heart  in  the  motion  of  red  blood. — Different 
proofs  of  this  influence. — Morbid  phenomena. — Dif- 
ferent experiments. — Observations. — General  Conse- 
quences. 336 

Of  the  limits  of  the  action  of  the  heart. — They  appear  to 
be  at  the  place  of  the  change  of  the  red  blood  into 
black. — Increasing  influence  of  the  arteries  upon  the 
red  blood  in  the  neighbourhood  of  the  capillaries.  342 


Phenomena  of  the  impulse  of  the  heart. — The  motion  of  the 
red  blood  is  sudden  and  instantaneous. — Proofs. — The 
contraction  of  the  arteries  does  not  push  the  blood. — 
From  what  it  arises. — The  causes  of  delay  are  nothing. 

— General  remarks.  334 

Remarks  upon  the  pulse. — The  arterial  locomotion  has  a 
great  part  in  it. — Of  the  accessory  causes. — Of  the 
varieties  of  the  pulse. — General  reflections.  348 

Sympathies. — They  are  in  general  rare  in  the  arteries. — 
Why.  352 


ARTICLE  FIFTH. 

DEVELOPMENT  OF  THE  VASCULAR  SYSTEM  WITH  RED  BLOOD. 

I.  State  of  this  System  in  the  Fcetus. 

The  two  systems  are  then  confounded. — There  is  but  one 
species  of  blood. — How  the  fcetus  can  live  with  black 
blood  alone. — Peculiar  mode  of  circulation  in  the  foetus. 

Consequences  which  result  from  it. Insensible 

change  of  this  mode  of  circulation. — How  it  takes  place. 

— Great  development  of  the  arteries  in  the  foetus.  354 


428 


ANALYTICAL  TABLE 


PARE 

II.  State  of  the  Vascvlar  System  with  Red  Blood  during  Growth. 

Sudden  formation  of  the  red  blood  at  birth. — Changes  in 
the  course  of  this  fluid. — Phenomena  and  causes  of 
these  changes. — Predominance  of  the  arteries  during 
youth.  364 

III.  State  of  the  Vascular  System  with  Red  Blood  after  Growth. 

Influence  of  the  genital  organs. — Varieties  of  the  influ- 
ence of  the  red  blood  according  to  the  ages.  371 

IV.  State  of  the  Vascular  System  with  Red  Blood  during  old  Jlge. 
Diminution  of  the  arterial  ramifications. — The  red  blood 

is  less  abundant. — The  arteries  are  condensed. — Pheno- 
mena of  the  pulse. — Of  the  pulse  in  the  last  moments 
of  life. — Experiments  upon  this  subject.  373 

V.  Accidental  Development  of  the  System  with  Red  Blood, 
There  are  two  kinds  of  it;  1st,  Dilatation  from  an  obstacle. 

2d,  Dilatation  from  any  tumour.  377 


VASCULAR  SYSTEM  WITH  BLACK  BLOOD, 


GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

SITUATION,  FORMS,  DIVISION  AND  GENERAL  ARRANGEMENT  OF  THE 
VASCULAR  SYSTEM  WITH  BLACK  BLOOD. 

I.  Origin  of  the  Veins. 

Manner  of  this  origin. — Two  orders  of  veins.  380 

II.  Course  of  the  Veins. 

Examination  of  this  course  on  the  exterior, and  the  interior.  881 

III.  Proportion  of  the  capacity  of  the  two  systems  with  Black 
and  Red  Blood. 

Remarks  upon  the  varieties  of  venous  capacit}L — Parallel 
between  the  two  vascular  apparatus  with  red  and  black 


OF  CONTENTS. 


429 


PAGE 

blood  in  this  respect. — General  consequences. — The 
velocity  is  in  an  inverse  ratio  of  the  capacity,  &c.  382 

Ramifications^  small  branches^  branches^  angles  of  union,  ^c. 

— Forms  of  the  Veins. — In  what  direction  these  vessels 
are  conical. — Relations  between  the  branches  and  their 
divisions.  388 

Anastomoses. — They  are  very  frequent. — Why. — Commu- 
nication between  the  external  and  the  internal  order. — 
Consequences. — Different  modes  of  anastomoses. — Their 
necessity  from  the  numerous  obstacles  to  the  course  of 
the  blood. — Of  these  obstacles.  392 

IV.  Termination  of  the  Veins. 

Mode  of  termination  in  the  heart. — Of  the  two  venous 
cones,  the  superior  and  the  inferior. — Of  their  commu- 
nication by  the  azygos.  396 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  VASCULAR  SYSTEM  WTTH  BLACK  BLOOD. 

I.  Texture  peculiar  to  this  Organization. 

Membrane  peculiar  to  the  ueins.— Manner  of  seeing  it. — Its 
longitudinal  fibres. — Varieties  of  these  fibres. — Their 
nature. — Peculiar  arrangement  of  the  cerebral  sinuses.  3 9 
Common  membrane  of  the  black  blood. — Its  differences  from 
that  of  the  red  blood. — More  extensibility. — Less  thick- 
ness.— No  disposition  to  ossify. — Consequences.  403 

Of  the  valves  of  the  veins. — Their  form. — Their  situation. 

— Veins  which  they  occupy. — Their  size. — Remarks 
upon  their  relations  with  the  caliber  of  the  veins. — 
Their  variety. — Their  number.  404 

Action  of  reagents  upon  the  venous  texture. — Action  of  the 
air,  water,  caloric,  the  acids,  &c.  407 

II.  Parts  common  to  the  Organization  of  the  Vasailar  System 
with  Black  Blood. 

Blood  vessels.  Cellular  texture. — Of  that  which  unites  the 
veins  to  the  neighbouring  parts. — Of  that  which  is 
peculiar  to  them.  408 


430 


ANALYTICAL  TABLE 


PAGE 

Exhalants  and  Msorbents. — Experiments  upon  venous  ab- 
sorption. 

.Serves. — There  are  but  very  few  of  them.  409 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  VASCULAR  SYSTEM  WITH  BLACK  BLOOD. 


I.  Properties  of  Texture. 

Extensibility. — It  is  very  evident. — Venous  ruptures  how- 
ever take  place. — Various  examples. — Their  causes 
are  but  obscurely  known.  411 

Contractility.— Of  this  property  in  the  longitudinal  and 
the  transverse  direction.  413 

II.  Vital  Properties. 

Properties  of  Animal  Life. — Result  of  the  experiments 
upon  sensibility. — There  is  no  contractility.  414 

Properties  of  organic  life.  Sensible  Contractility. — It  ap- 
pears to  be  but  slight. — General  remarks.  415 

Of  the  venous  pulse. — Of  its  cause. — It  is  a reflux. — Double 
cause  which  produces  it.  416 

Insensible  Contractility. — It  appears  to  exist. — The  vital 
activity  is  greater  in  the  veins  than  in  the  arteries. — 
Consequences.  419 


Observations  on  the  motion  of  the  black  blood  in  the  veins. — 
There  is  no  pulse  analogous  to  that  of  the  arteries. — 
Agent  of  impulse  of  the  venous  blood. — Causes  of  de- 
lay— Accessory  causes  of  motion. — Resemblance  be- 
tween the  motion  of  the  veins  and  that  of  the  arteries.  420 
Sympathies  of  the  veins. — They  are  very  obscure.  424 


.ARTICLE  FOURTH. 

DEVKLOPMEMT  OF  THE  VASCULAR  SYSTEM  WITH  BLACK  BLOOD. 

I.  State  of  this  System  in  the  Foetus. 

The  veins  are  less  developed  in  proportion  than  the  arte- 
ries.—Why. — Remarks.  425 


OF  CONTENTS. 


431 


PAGE 

II.  State  of  this  System  during  Growth  and  afterwards. 
Various  phenomena  of  childhood,  adult  age,  &c.  427 

III.  State  of  this  System  in  Old  Age. 

The  veins  are  much  developed  in  old  age. — This  deve- 
lopment is  only  a dilatation. — Its  varieties  according  to 
different  circumstances.  428 


IV.  Accidental  Development  of  the  Veins. 

It  must  he  considered,  1st,  in  tumours;  2d,  in  the  disten- 
sions of  the  different  parts.  430 


ARTICLE  FIFTH. 

REJURKS  UPON  THE  PULMONARY  ARTERY  AND  VEINS. 

Though  the  two  kinds  of  blood  are  separate,  yet  the 
mechanical  phenomena  of  their  courses  are  analogous 
in  the  aorta  and  the  pulmonary  artery,  and  in  the 
general  and  the  pulmonary  veins.  ib. 


ARTICLE  SIXTH. 

ABDOMINAL  VASCULAR  SYSTEM  WITH  BLACK  BLOOD. 

Situation,  forms,  general  arrangement,  anastomoses,  fyc. — 
Origin  and  termination  in  the  capillaries. — Abdominal 
portion.— Hepatic  portion. — Differences  between  them.  433 
Organization,  properties,  4i‘C. — Analogy  with  the  veins  in 
this  respect. — Peculiar  arrangement  in  the  hepatic 
portion.— Absence  of  valves. — Why.  436 

Remarks  upon  the  motion  of  the  black  abdominal  blood. — 
Comparison  between  the  liver  and  the  lungs. — Their 
difference  as  it  regards  the  blood  that  goes  to  them. — 
Mechanism  of  the  circulation  of  this  system. — Influence 
of  the  accessory  causes.  438 

Remarks  upon  the  liver. — It  performs  another  function  be- 
sides the  secretion  of  bile. — Proofs. — We  are  ignorant 
of  this  function. — It  must  be  extremely  important. — 
Various  proofs. — The  liver  exhibits  phenomena  that  no 


433 


ANALYTICAL  TABLE  OF  CONTENTS. 


PAGE 

other  gland  does. — It  is  not  certain  that  the  black  ab- 
dominal blood  serves  for  the  secretion  of  bile. — Proofs. 

— General  observations. — Experiments.  440 

Remarks  upon  the  course  of  the  bile. — Course  of  this  fluid 
during  abstinence  and  during  digestion. — Cystic  bile. — 
Hepatic  bile. — Reflux  towards  tbe  stomach  during  va- 
cuity and  fulness. — Experiments.  446 

Development. — There  is  only  one  vascular  system  in  the 
foetus. — It  is  divided  into  three  at  birth. — State  of  the 
umbilical  vein  and  the  vena  porta  in  the  foetus. — Rela- 
tive size  of  the  liver  at  this  period. — Phenomena  at 
birth. — Different  influences  of  this  system  in  the  follow- 
ing ages.  450 


END  OF  CONTENTS  TO  VOL.  I. 


VOLUME  SECOND. 


CAPILLARY  SYSTEMS. 


There  are  two  of  them. — Their  general  arrangement 
Their  opposition. 


ARTICLE  FIRST. 

OF  THE  GENERAL  CAPILLARY  SYSTEJI. 

General  arrangement  of  this  system.  4 

I.  General  division  of  the  Capillaries. 

Of  the  organs  in  which  the  capillaries  contain  only  blood.  6 

Of  the  organs  in  which  the  capillaries  contain  blood  and fluids 
differing  from  it. — Serous  system  taken  for  an  example. 

— Experiments  hy  injections. — Various  other  systems 
present  analogous  facts. — Proportion  of  the  blood  and 
the  fluids  difiering  from  it.  ib. 

Of  the  organs  in  which  the  capillaries  do  not  contain  blood.  8 

II.  Difference  of  Organs  in  respect  to  the  number  of  their 
Capillaries. 

There  are  many  classes  of  organs  in  this  respect. — Why 
the  capillaries  are  very  much  developed  in  some. — 
Consequences  as  it  regards  diseases.  9 

Remarks  upon  injections. — Their  insufficiency  in  making 
us  acquainted  with  the  small  vessels.  10 

III.  Of  the  proportions  which  exist  in  the  Capillaries  between  the 
Blood  and  the  Fluids  that  differ  from  it. 

Continual  varieties  in  the  proportion. — Cause  of  these 
varieties. — They  are  very  numerous. 

VOL.  III.  55 


PAGE. 

3 


12 


434 


ANALYTICAL  TABLE 


PAGE 

Different  proportions  of  blood  in  the  capillaries^  according  as 
the  secretions  and  exhalations  are  active  or  passive. — Of 
active  and  passive  exhalations. — Of  secretions  of  the 
same  nature. — Examination  of  each. — Proofs  that 
wherever  there  is  activity, blood  enters  the  capillaries. 

— Opposite  arrangement  in  the  passive  [thenomena.  1 

Consequences  of  the  preceding  Remarks.  1 

IV.  Of  the  Anastomoses  of  the  General  Capillary  System. 

Mode  of  these  anastomoses. — The  capillaries  considered  in 
relation  to  the  vessels  with  which  they  communicate. — 
Influence  of  these  communications. — Important  ob- 
servation in  regard  to  the  examination  of  dead  bodies. 

— How  acute  inflammations  disappear  at  death,  17 

V.  How.,  notwithstanding  the  general  communication  of  the  Capil- 
lary System,  the  Blood  and  the  Fluids  differing  from  it,  remain 
separate. 

This  depends  on  the  different  modifications  of  the  organic 
sensibility. — Proofs. — General  remarks.  21 

VI.  Consequences  of  the  preceding  principles,  in  relation  to  In- 

flammation. 

Every  thing  arises,  in  this  affection,  from  the  alteration 
of  the  organic  sensibility. — Proofs. — Varieties  of  inten- 
sity and  nature  in  inflammations. — Terminations  of  in- 
flammations.— Of  putrefaction. — Of  death. — Of  indura- 
tion.— Of  the  blood  which  stops  in  inflamed  parts.  24 

Differences  of  inflammation  according  to  the  different  sys- 
tems.— Each  has  a peculiar  one. — Of  those  whicli  are 
the  most  disposed  to  it. — It  has  peculiar  modifications 
in  each. — Same  observation  in  regard  to  its  termina- 
tions. 30 

VII.  Structure  and  Properties  of  the  Capillaries. 

We  cannot  ascertain  comjilelely  the  structure. — It  has 
however  varieties.  35 

VIII.  Of  the  Circulation  of  the  Capillaries. 

Motions  of  the  fluids  in  the  Capillary  System. — The  blood  is 
independent  of  the  action  of  the  heart  in  the  capilla- 
ries.— Various  proofs  of  this  assertion. — The  hlood 
circulates  by  the  influence  of  the  forces  of  the  part. — 
Varieties  of  the  motions. — Causes  of  these  varieties. — 
Influence  of  the  atmosphere  upon  the  capillary  circula- 


cri  I- 


OF  CONTENTS. 


435 


PAGE 

tion. — Of  the  two  kinds  of  bleeding  in  relation  to  the 
capillaries  and  to  the  trunks. — Circulation  of  other 
fluids  than  the  blood  in  the  capillaries.  34 

Phenomena  af  the  alteration  of  the  fluids  in  the  Capillary 
System. — Change  of  the  red  blood  to  black. — Phenom- 
ena of  this  change.  41 

IX.  Of  the  Capillaries  considered  as  the  seat  of  the  production  of 

Heat. 

Different  hypotheses. — Phenomena  of  animal  heat. — How 
it  is  produced. — Analogy  of  the  production  of  heat 
with  exhalation,  secretion,  &c. — Influence  of  the  differ- 
ent vital  forces. — Explanation  of  the  phenomena  of 
animat  heat  in  the  state  of  health  and  disease. — Sym- 
pathetic heat. — Sympathies  of  heat. — Difference  be- 
tween the  two.  43 


- ARTICLE  SECOjSTD. 

PULM0N.4RY  CAPILLARY  SYSTEM. 

I.  Relation  of  the  two  Capillary  Systems,  Pulmonary  and  General. 

How  all  the  blood  of  the  general  system  can  go  through 
the  pulmonary. — Difference  of  one  from  the  other  as  it 
respects  the  course  of  this  fluid.  65 

II.  Remarks  upon  the  Circidation  of  the  Pulmonary  Capillaries. 

Peculiar  character  of  pulmonary  inflammations. — Phe- 
nomena to  which  they  give  rise. — Of  the  pulmonary 
circulation  in  various  other  diseases.  58 

III.  Alteration  of  the  Blood  in  the  Pulmonary  Capillaries.  63 

IV.  Remarks  upon  the  state  of  the  Lungs  in  Dead  Bodies. 

Their  proportions  very  various  from  engorgement. — They 
are  hardly  ever  in  the  natural  state. — Why. — Conse- 
quences. 64 


436 


ANALYTICAL  TABLE 


EXHALANT  SYSTEM. 


PAGE 

General  Remarks  upon  the  differences  of  exhalations  and 
absorptions.  67 


ARTICLE  FIRST. 

GENERAL  ARRANGEMENT  OF  THE  EXIIALANTS. 

I.  Origin,  Course  and  Termination. 

Different  hypotheses  respecting  these  vessels. — What  ob- 
servation shows  us  concerning  them.  69 

II.  Division  of  the  Exhalants. 

They  can  be  referred  to  three  classes. — Table  of  these 
classes  and  their  division.  71 

III.  Difference  of  the  Exhalations.  73 


ARTICLE  SECOND. 

PROPERTIES,  FUNCTIONS  AND  DEVELOPMENT  OF  THE ' EXHALANT 
SYSTEM. 

4. 

I.  Properties. 

We  are  ignorant  of  those  of  texture. — The  organic  are 
very  evident  in  it.  74 

Characters  of  the  Vital  Properties.' — They  vary  in  each  sys- 
tem.— Consequences  as  it  regards  functions.  ib. 

II.  Of  Katural  Exhalations. 

They  are  all  derived  from  the  vital  properties. — They 
vary  consequently  like  these  properties. — Proofs. — Of 
sympathetic  exhalations.  75 


OF  CONTENTS. 


437 


PAGE 

III.  Of  Preternatural  Exhalations. 

Sanguineous  exhalation. — Hemorrhage  of  the  excrementitious 
exhalants. — Hemorrhage  from  the  skin. — Hemorrhages 
from  the  mucous  surfaces. — They  take  place  by  exha- 
lation.— Proofs. — Experiments. — Of  active  and  passive 
hemorrhages. — Differences  between  hemorrhages  by 
rupture  and  by  exhalation,  between  those  of  the  capil- 
laries and  those  of  the  great  vessels.  78 

Hemorrhages  of  the  recrementitious  exhalants. — Hemorrhages 
of  the  serous  surfaces. — Observations  concerning  dead 
bodies. — Cellular  hemorrhages. — Other  hemorrhages 
of  the  exhalants.  85 

Preternatural  exhalations,  not  sanguineous. — Varieties  of  the 
exhaled  fluids,  according  to  the  state  of  the  vital  forces 
of  the'exhalants. — Different  examples  of  these  varie- 
ties. 87 

IV.  Of  the  preternatural  development  of  the  exhalants. 

It  is  especially  in  cysts  that  it  fakes  place. — The  secreted 
fluids  are  never  preternaturally  poured  out  like  the  ex- 
haled.— Why. — Of  the  natural  emunctories.  88 


ABSORBENT  SYSTEM. 


GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

or  THE  ABSORBENT  VESSELS. 

I.  Origin  of  the  Absorbents. 

Table  of  absorptions. — Of  external  absorptions. — Of  in- 
ternal absorptions. — Of  the  nutritive  absorptions. — It  is 
impossible  to  know  the  mode  of  origin  of  the  absorb- 
ents.— Interlacing  of  the  branches.  91 

II.  Course  of  the  Absorbents. 

Their  division  into  two  la}'ers,  superficial  and  deep-seated. 

— Their  arrangement  in  the  extremities  and  the  trunk.  95 


43d 


ANALYTICAL  TABLE 


PAGE 

Forms  of  the  absorbents  in  their  course. — They  are  cylindri- 
cal, full  of  knots,  &c. — Consequences  of  these  forms. — 

The  absorbents  have  not  as  great  capacity  during  life 
as  in  the  dead  body.  97 

Of  the  capacity  of  the  absorbents  in  their  course. — Manner 
of  ascertaining  it. — Extreme  varieties  which  it  exhib- 
its.— Capacity  of  the  absorbents  compared  with  that  of 
the  veins.  99 

Anastomoses  of  the  absorbents  in  their  course. — Different 
modes  of  these  anastomoses. — Remarks  upon  the  lym- 
phatic circulation.  102 

Remarks  upon  the  difference  of  dropsies  that  are  produced 
by  the  increase  of  Exhalation.,  and  those  tfyat  are  the  effect 
of  a diminution  of  absorption. — Cases  that  may'  be  re- 
ferred to  one  or  the  other  cause.  104 

III.  Termination  of  the  Absorbents. 

Trunks  of  termination. — Their  disproportion  with  the 
branches. — Consequences. — Difficulties  in  regard  to  the 
motion  of  the  lymph. — Remarks  upon  venous  absorp- 
tion. 105 

IV.  Structure  of  the  Absorbents. 

Exterior  texture. — -Vessels. — Peculiar  membrane.' — 
Valves. — Uses  of  these  last.  109 


ARTICLE  SECOND. 

LYMPHATIC  GL-ilNDS. 

I.  Situation.,  Size.,  Forms,  fyc. 

Varieties  of  their  number  and  situation  in  the  different 
regions. — Relation  with  the  cellular  texture. — Varieties 
from  age,  sex,  &c.  1 1 1 

II.  Organization. 

Colour. — Its  varieties. — Particular  arrangement  about  the 
bronchia.  114 

Common  parts. — External  cellular  texture.— Cellular  mem- 
brane.— Vessels.  115 

Peculiar  texture. — Density. — Cells. — Contained  fluid. — 
Properties  and  phenomena  of  this  texture.— Interlacing 
of  the  absorbents.  IIG 


OF  CONTENTS. 


439 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  ABSORBENT  SYSTEM. 


PAGE 

I.  Properties  of  Texture.  118 

II.  Vital  Properties. 

Animal  sensibility. — Its  phenomena  in  the  vessels  and  the 

glands. — Organic  properties. Their  duration  after 

death. — Remarks  upon  the  absorbent  faculty  of  dead 
bodies.  119 

Characters  of  the  vital  properties. — Life  is  very  evident  in 
this  system. — Its  disposition  to  inflammation. — Charac- 
ter which  this  affection  has  in  it.  122 

Differences  of  the  vital  properties  in  the  absorbent  vessels 
and  their  glands. — These  differences  are  remarkable. — 
Their  influence  upon  diseases.  123 

Sjpnpathies. — Sympathies  of  the  glands. — Sympathies  of 
the  vessels. — Remarks  upon  the  engorgements  of  the 
lymphatic  glands.  124 


ARTICLE  FOURTH. 

OF  ABSORPTION. 

I.  Infivence  of  the  Vital  Forces  upon  this  Function. 

All  depends  on  the  organic  properties.  128 

II.  Varieties  of  Absorption. 

Difierent  examples. — Of  resolution. — Of  the  absorption 
of  morbilic  principles.  129 

III.  Motion  of  the  Fluids  in  the  Absorbents. 

Laws  of  this  motion. — It  is  not  subject  to  any  reflux. — 
Why.  132 

IV.  Of  Absorption  in  the  different  Ages. 

It  appears  that  the  internal  and  external  absorptions  are 
opposite  at  the  two  extreme  ages. — Remarks. 


134 


440 


ANALYTICAL  TABLE 


PAGE 


V.  Preternatural  Absorption. 

Absorption  of  certain  fluids  different  from  those  naturally 
absorbed. — Absorption  in  the  cysts.  138 


SYSTEMS  PECULIAR  TO  CERTAIN  APPA- 
RATUS. 


GENERAL  OBSERVATIONS. 

Differences  of  the  systems  peculiar  to  certain  apparatus, 
from  those  common  to  all. — Characters  of  the  first. — 
Their  distribution  in  the  apparatus.  139 


OSSEOUS  SYSTEM. 


GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

OF  THE  FORMS  OF  THE  OSSEOUS  SYSTEM.  DIVISION  OF  THE  BONES. 

I.  Of  the  Ixing  Bones. 

Relation  of  their  position  with  their  general  uses. — Ex- 
ternal forms  of  the  body  and  the  extremities. — Internal 

forms. — Medullary  canal. Its  situation,  extent  and 

form. — Its  use. — It  disappears  in  the  first  periods  of 
callus. — It  is  shorter  in  proportion  in  childhood.  144 

II.  Of  the  Flat  Bones. 

Relations  of  their  situation  and  external  forms  with  the 
general  use  of  forming  the  cavities. — Internal  forms.  147 


OF  CONTENTS, 


441 


III.  Of  the  Short  Bones. 

Position. — Internal  and  external  forms. — General  uses. 

IV.  Of  the  Bony  Eminences. 

Their  division  into  those,  1st,  of  articulation ; 2d,  of  inser- 
tion ; 3d,  of  reflection ; 4th,  of  impression. — Remarks 
upon  each  of  these  divisions. — Relations  of  the  second 
with  the  muscular  force. — Plow  these  last  are  formed. 

V.  Of  the  Osseous  Cavities. 

Their  division  into  those,  1st,  of  insertion  ; 2d,  of  recep- 
tion ; 3d,  of  sliding ; 4th,  of  impression  ; 5th,  of  trans- 
mission ; 6th,  of  nutrition. — Particular  remarks  upon 
each  division. — Of  the  three  kinds  of  canals  of  nutrition. 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  OSSEOUS  SYSTEM. 


I.  Texture  Peculiar  to  the  Osseous  System. 

Common  division  of  this  texture. 

Texture  with  cells. — How  it  is  formed. — When  it  is  formed. 
— Of  the  cells  and  their  communications. — Experi- 
ments. 

Compact  texture. — Arrangement  of  its  fibres. — Their  for- 
mation.— Experiments  to  ascertain  their  direction. — 
The  osseous  layers  do  not  exist. — Proofs. — Influence 
of  rickets  upon  the  compact  texture. 

Arrangement  of  the  two  osseous  textures  in  the  three  kinds  of 
Bones. — Arrangement  of  the  compact  texture. — Two 
kinds  of  texture  with  cells  in  the  long  bones. — Propor- 
tion of  the  common  texture  with  cells  and  the  compact 
texture  in  the  short  and  broad  bones. — The  same  pro- 
portion examined  in  the  cavities  and  the  osseous  emi- 
nences. 

Of  the  composition  of  the  osseous  texture. — There  are  two 
principal  bases. — Of  the  saline  calcareous  substance. — 
Experiments. — Nature  of  this  substance. — Experiments 
to  ascertain  the  gelatinous  substance. — Different  rela- 
tions of  each  of  these  substances  with  vitality. 
roL.  m.  56 


AGE 

149 


150 


153 


156 


158 


161 


164 


442 


ANALYTICAL  TABLE 


PAOE 

11.  Common  Parts  which  enter  into  the  organization  of  the 
Osseous  System. 


Three  orders  of  blood  vessels. — Arrangement  of  each. — 
Experiments. — Proportions  according  to  age. — Com- 
munication.— Proofs  of  the  existence  of  the  cellular 
texture.  167 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  OSSEOUS  SYSTEM. 

L Physical  Properties. 


Elasticity. — It  is  in  the  inverse  ratio  of  the  age.  171 

II.  Properties  of  Texture. 

Ditferent  examples  of  contractility  and  extensibility. — 
Characters  of  these  properties.  171 

III.  Vital  Properties. 

They  are  obscure.  173 

Characters  of  these  properties. — Slowness  of  their  develop- 
ment.— Their  influence  upon  diseases.  174 

Sympathies. — Their  character  is  always  chronic. — Gene- 
ral remark  upon  sympathies.  175 

Seat  of  the  vital  properties — They  are  not  seated  in  the  cal- 
careous substance. — They  exist  only  in  the  gelatinous. 

— Experiment  which  proves  it.  177 


ARTICLE  FOURTH. 

OF  THE  APvTICULATIONS  OF  THE  OSSEOUS  SYSTEM. 

I.  Division  of  the  Articulations. 

Moveable  Articulations. — Observations  upon,  their  Motions. — 

1st.  Opposition  ; it  is  extensive  or  confined. — 2d.  Cir- 
cumduction ; a motion  composed  of  all  those  of  oppo- 
sition.— 3d.  Rotation;  a motion  upon  the  axis.— 4th. 
Sliding.  180 


OF  CONTENTS, 


443 

PAGE 

Immoveable  articulations. — They  are  on  surfaces  in  juxta- 
position, inserted  into  each  other  or  implanted.  182 

Table  of  the  Articulations.  183 

II.  Observations  upon  the  Moveable  Articulations. 

First  genus. — Situation. — Form  of  the  surfaces. — Rotation 
and  circumduction  are  inversely  in  the  humerus  and 


the  femur. — Why.  184 

Second  genus. — Form  of  the  surfaces. — Motions.  186 

Third  genus. — Diminution  of  the  motions. — Direction  in 
which  they  take  place.  187 

Fourth  genus. — Motions  still  less.  189 

Fifth  genus. — Remarkable  obscurity  of  the  motions.  190 


III.  Observations  upon  the  Immoveable  Articulations. 

Situation,  forms  of  each  order. — Relation  of  the  structure  191 
to  the  uses. 

IV.  Of  the  means  of  Union  between  the  Articular  Surfaces. 

Union  of  the  immoveable  Articulations. — Cartilages  of  union,  193 
Union  of  moveable  articulations. — Ligaments  and  muscles 
considered  as  articular  bands.  194 


ARTICLE  FIFTH. 

DEVELOPMENT  OF  THE  OSSEOUS  SYSTEM. 


Remarks.  195 

I.  Slate  of  the  Osseous  System  during  Growth. 

.Mucous  State. — What  should  be  understood  by  it.  195 

Cartilaginous  State. — Period  and  mode  of  its  development. 

— Of  this  state  in  the  broad  bones.  197 

Osseous  State. — Its  phenomena. — Its  period.  198 

Progress  of  the  osseous  state  in  the  long  bones ; 1st,  in  the 
middle  ; 2d,  in  the  extremities.  200 

Progress  of  the  osseous  state  in  the  broad  bones. — Varieties 
according  to  the  bones.  Formation  of  the  ossa  wormi- 
ana.  ib. 

Progress  of  the  osseous  state  in  the  short  bones.  202 


444 


ANALYTICAL  TABLE 


PAGE 

II,  Stale  of  the  Osseous  System  after  its  Growth. 

Increase  in  thickness. — Composition  and  decomposition 
after  the  termination  of  growth  in  thickness. — Experi- 
ments.— State  of  the  bones  in  old  age.  203 

III.  Peculiar  Phenomena  of  the  Development  of  the  Callus. 

1st.  Fleshy  granulations. — 2d.  Adhesions  of  these  granu- 
lations.— 3d.  Exhalation  of  gelatine  and  then  of  phos- 
phate of  lime.  206 

IV.  Peculiar  Phenomena  of  the  Development  of  the  Teeth. 

Organization  of  the  teeth. — Hard  portion  of  the  teeth. — 
Enamel. — Experiment  which  distinguishes  it  from 
bone. — Its  thickness. — Its  nature. — Reflections  upon 
its  organization. — Osseous  portion. — Its  form. — Cavity 
of  the  tooth.  209 

Soft  portion  of  the  tooth. — Its  spongy  nature. — Its  acute 
sensibility. — Remarks  upon  its  different  sympathies.  211 

First  dentition  considered  before  cutting. — Follicle. — Mem- 
brane of  this  follicle  analogous  to  the  serous  mem- 
branes.— Albuminous  nature  of  the  fluid  which  lubri- 
cates it. — Mode  of  development  of  the  osseous  tooth 
upon  the  I'ollicle. — Number  of  the  first  teeth.  213 

First  dentition  considered  at  the  period  of  cutting. — Mode 
of  cutting. — Accidents. — Their  causes.  216 

Second  dentition  considered  before  cutting. — Formation  of 
the  second  follicle.  217 

Second  dentition  considered  at  the  period  of  cutting. — Fall 
of  the  first  teeth. — Appearance  of  the  second. 

Phenomena  subsequent  to  the  cutting  of  the  second  teeth. — 
Growth  in  length  and  thickness. — Fall  of  the  teeth 
earlier  than  the  death  of  the  hones. — Why. — State  of 
the  jaws  after  the  fall  of  the  teeth.  219' 

V.  Particular  Phenomena  of  the  Development  of  the  Sesa- 

moid Bones. 

General  arrangement  of  the  sesamoid  bones. — Situation. — 
Forms.  221 

Fibro-cartilaginous  state. — Osseous  state. — Phenomena  of 
the  patella. — Use  of  the  sesamoid  bones.  222 


OF  CONTENTS. 


445 


MEDULLARY  SYSTEM. 

PAGE 

Division  of  this  system.  225 


ARTICLE  FIRST. 

MEDULLARY  SYSTEM  OF  THE  FLAT  AND  SHORT  BONES,  AND  THE 
EXTREMITIES  OF  THE  LONG  ONES. 

I.  Origin  and  Conformation. 

It  is  an  expansion  of  the  vessels  of  the  second  order.  225 

II.  Organization. 

There  is  no  medullary  membrane. — Vascular  interlacing.  226 

III.  Properties. 

There  are  only  organic  ones. — Experiments.  227 

IV.  Development. 

There  is  no  medullary  oil  in  infancy. — Proofs. — Experi- 
ments. 227 

ARTICLE  SECOND. 

MEDULLARY  SYSTEM  OF  THE  MIDDLE  OF  THE  LONG  BONES. 

I.  Conformation. 

It  is  like  the  cellular. 

II.  Organization. 

The  medullary  membrane  is  not  an  expansion  of  the  peri 
osteum. — Its  vessels. 

III.  Properties. 

Properties  of  texture. — Vital  properties. — Animal  sensi 
bility. — Vitality  more  active  than  in  the  bones. 


229 


230 


231 


446 


ANALYTICAL  TABLE 


PAGE 


IV.  Development. 

How  the  medullary  membrane  is  formed. — The  marrow 
of  the  infant  is  wholly  different  from  that  of  the  adult. 

— Proofs.  233 

Functions. — The  marrow  is  exhaled. — Its  alterations. — Its 
relations  with  the  nutrition  of  the  bone. — Necrosis. — 

The  marrow  is  foreign  to  the  synovia.  234 


CARTILAGINOUS  SYSTEM. 


What  must  be  understood  by  cartilage. 


237 


ARTICLE  FIRST. 

OF  THE  FORMS  OF  THE  CARTILAGINOUS  SYSTEM. 

I.  Forms  of  the  Cartilages  of  the  Moveable  Articulations. 

Internal  and  external  surfaces. — Relations  of  the  two  cor- 
responding cartilages. — Peculiar  characters  of  these 
cartilages  in  each  kind  of  moveable  articulations.  238 

II.  Forms  of  the  Cdrlilages  of  the  Immoveable  Articula- 
tions. 241 

III.  Forms  of  the  Cartilages  of  the  Cavities.  242 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  CARTILAGINOUS  SYSTEM. 

I.  Texture  peculiar  to  the  Cartilaginous  System. 

Fibres. — Remarkable  resistance  of  the  cartilaginous  tex- 
ture to  putrefaction,  maceration,  &c. — Stewing  and  de- 
siccation of  this  texture. — Its  various  alterations.  243 


OF  CONTENTS. 


447 


PAGE 

II.  Parts  common  to  the  Organization  of  the  Cartilaginous 
Texture. 

Cellular  texture. — Means  of  seeing  it. — Absence  of  blood 
vessels. — White  vessels. — Their  colour  in  jaundice.  24.'> 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  CARTILAGINOUS  SYSTEM. 

I.  Physical  Properties, 


Elasticity. — It  appears  to  be  owing  to  the  superabundance 
of  gelatine. — Proofs.  247 

II.  Properties  of  Texture. 

They  are  very  obscure.  248 

III.  Vital  Properties. 

They  are  inconsiderable,  as  well  as  the  sympathies.  249 

Character. of  the  Vital  Properties. — All  the  phenomena  over 
which  they  preside  have  a chronic  progress. — General 
observations  upon  the  reunion  of  the  parts.  250 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  CARTILAGINOUS  SYSTEM. 

I.  State  of  the  Cartilaginous  System  in  the  First  Age. 

Predominance  of  gelatine  in  the  early  periods. — Property 
which  the  cartilages  then  have  of  becoming  red  by 
maceration. — Vascular  layers  between  the  cartilage 
and  the  bone. — Cause  which  limits  ossification  in  the 
cartilage. — Development  of  the  cartilages  of  the  cav- 
ities. 252 

II.  S/rt/e  of  the  Cartilaginous  System  in  the  after  Ages. 

Different  character  which  the  gelatine  assumes. — Ossifi- 
cation of  the  cartilages  in  old  age.— Those  of  the  cavi- 
ties are  the  soonest  ossified.  255 


448 


ANALYTICAL  TABL£ 


PAGE 

III.  Preternatural  Development  of  the  Cartilaginous  System. 

Tendency  of  the  membrane  of  the  spleen  to  become  the 
seat  of  it. — Preternatural  cartilages  of  the  articula- 
tions. 257 


FIBROUS  SYSTEM. 


GENERAL  OBSERVATIONS. 

ARTICLE  FIRST. 

OF  THE  FORMS  AND  DIVISIONS  OF  THE  FIBROUS  SYSTEM. 

The  fibrous  forms  are  either  membranous  or  in  fasci®.  259 

I.  Of  the  Fibrous  Organs  of  a Membranous  Form. 

Fibrous  membranes. — Fibrous  capsules. — Fibrous  sheaths. 

— Aponeuroses.  260 

II.  Of  the  Fibrous  Organs  in  the  form  of  Fascice. 

1st.  Tendons. — 2d.  Ligaments.  262 

III.  Table  of  the  Fibrous  System. 

Analogy  of  the  different  organs  of  this  system. — The 
periosteum  is  the  common  centre  of  these  organs.  262 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  FIBROUS  SYSTEM. 

I.  Of  the  Texture  peculiar  to  the  Organization  of  the  Fibrous 

System. 

Peculiar  nature  of  the  fibrous  texture. — Its  extreme  re- 
sistance.— Phenomena  of  this  resistance. — It  can  be 


OF  CONTENTS. 


449 


PAGE 

overcome. — Difference  of  the  fibrous  and  muscular  tex- 
tures.— Experiments  upon  the  fibrous  texture  subject- 
ed to  maceration,  ebullition,  putrefaction,  the  action  of 
the  acids,  the  digestive  juices,  &c.  264 

II.  Of  the  Common  Parts  which  enter  into  the  Organization 
of  the  Fibrous  System. 

Cellular  texture. — Blood  vessels. — Their  varieties  accord- 
ing to  the  organs.  270 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  FIBROUS  SYSTEM. 

I.  Physical  Properties. 

II.  Properties  of  Texture. 

Extensibility. — Peculiar  law  to  which  it  is  subjected  there. 
Contractility. — It  is  almost  nothing. — When  it  is  mani- 
fested. 272 


III.  Vital  Properties. 

Animal  sensibility. — Singular  mode  of  putting  it  in  action 
by  distension. — Consequence  of  this  peculiar  phenome- 
non to  the  fibrous  texture.  274 

Character  of  the  vital  properties. — The  vital  activity  is  more 
evident  in  this  system  than  in  the  preceding, — It  ap- 
pears that  the  fibrous  texture  does  not  suppurate.  277 
Sympathies. — Examples  of  those  of  the  animal  and  the  or- 
ganic properties.  279 


' ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  FIBROUS  SYSTEM. 

I.  Stale  of  the  Fibrous  System  in  the  First  Jlge. 

The  fibres  are  wanting  in  most  of  the  fibrous  organs  of 
the  foetus. — Softness  of  these  organs  at  this  age. — 
Varieties  of  development. — Remarks  upon  rheumatism.  281 
VOL.  III.  57 


450 


ANALYTICAL  TABLE 


PAGE 

II.  Slate  of  the  Fibrous  System  in  the  After  Ages. 
Phenomena  of  the  adult. — General  stiffness  in  old  age.  283 

III.  Preternatural  Development  rf  the  Fibrous  System. 

Various  tumours  exhibit  fibres  analogous  to  those  of  this 
system.  284 


ARTICLE  FIFTH. 

OF  THE  FIBROUS  MEMBRANES  IN  GENERAL. 

I.  Forms  of  the  Fibrous  Membranes. 

Their  double  surface. — These  membranes  are  like  moulds 
of  their  respective  organs. — Researches  respecting  that 


of  the  corpus  cavernosum. — Experiments  which  show 
that  it  differs  essentially  from  the  subjacent  spongy  tex- 
ture.— Other  researches  upon  that  of  the  testicle.  285 

II.  Organization  of  the  Fibrous  Membranes.  288 

HI.  Of  the  Periosteum.  Of  its  Form. 

Its  two  surfaces. — Their  adhesion  to  the  bones.  289 

Organization  of  the  periosteum. — Preternatural  develop- 
ment of  its  fibres  in  elephantiasis. — Its  connexions  with 
the  fibrous  bodies  in  infancy,  291 

Development  of  the  periosteum. 

Functions  of  the  Periosteum. — In  what  way  it  assists  ossifi- 
cation.— It  relates  as  much  to  the  fibrous  organs  as  to 
the  bones.  292 

IV.  Perichondrium. 

Experiments  upon  this  membrane.  294 


ARTICLE  SIXTH. 

OF  THE  FIBROUS  CAPSULES. 

I.  Forms  of  the  Fibrous  Capsules. 

They  are  very  few. — Arrangement  of  the  two  principal 
ones. — Canal  between  them  and  the  synoviai  capsule.  295 

II.  Functions  of  the  Fibrous  Capsules.  296 


OF  CONTENTS. 


451 


ARTICLE  SEVENTH.' 

OF  THE  FIBROUS  SHEATHS. 

PAGE 

Their  division.  297 

I.  Partial  Fibrous  Sheaths. 

Their  form. — Their  arrangement. — Why  the  flexor  ten- 
donsare  alone  provided  with  them.  297 

II.  General  Fibrous  Sheaths.  299 


ARTICLE  EIGHTH. 

OF  THE  APONEUROSES. 

I.  Of  the  Aponeuroses  for  Covering. 

Their  division  299 

Aponeuroses  for  general  covering.  300 

Forms. — They  are  accommodated  to  the  extremities,  &c.  ib. 
Tensor  muscles. — Organization. — Examples  of  the  tensor 
muscles. — Their  uses  relative  to  the  aponeuroses. — 
Analogy  with  the  tendons  and  difference  from  them. 

— Arrangement  of  the  fibres.  301 

Functions.  - 302 

Aponeuroses  for  partial  covering. — Examples. — General 
uses  of  these  aponeuroses.  303 

II.  Of  the  Aponeuroses  of  Insertion. 

Aponeuroses  of  insertion  with  a broad  surface. — Their  ori- 
gin.— Their  uses. — The  identity  of  their  nature  with 
that  of  the  tendons. — Experiments.  304 

Aponeuroses  of  insertion  in  the  form  of  an  arch. — They  are 
rare. — They  exist  where  vessels  pass  through. — They 
do  not  compress  them.  305 

Aponeuroses  of  insertion  with  separate  fibres.  306 


452 


ANALYTICAL  TABLE 


ARTICLE  NINTH. 

OF  THE  TENDONS. 


I.  Form  of  the  Tendons. 


Relation  of  the  uses  with  the  forms.- 
fleshy  fibres. 


PACE 


-Union  with  the 


307 


II.  Organization  of  the  Tendons. 

Method  of  seeing  their  fibres  advantageously. — They  ap- 
pear to  be  destitute  of  blood  vessels. — Their  tendency 
to  be  penetrated  with  the  phosphate  of  lime.  309 


ARTICLE  TENTH. 

OF  THE  LIGAMENTS. 

I.  Ligaments  with  Regular  Fascia. 

General  arrangement.  31 1 

II.  Ligaments  with  Irregular  Fascia.  312 


FIBRO-CARTILAGINOUS  SYSTEM. 


Organs  which  compose  it. 


315 


ARTICLE  FIRST. 

OF  THE  FORMS  OF  THE  FIBRO-CARTILAGINOUS  SYSTEM. 

Division  into  three  classes  of  the  organs  of  this  system. 

— Characters  of  each  class.  315 


OF  CONTENTS. 


453 


r 

ARTICLE  SECOND. 


ORGANIZATION  OF  THE  FIBRO-CARTILAGINOUS  SYSTEM. 


I.  Texture  peculiar  to  the  Organization  of  the  Fibro- 
cartilaginous System. 


PAGE 

It  arises,  1st,  from  a fibrous  substance  ; 2d,  from  a cartila- 
ginous one. — It  owes  its  resistance  to  the  first  and  its 
elasticity  to  the  second. — Action  of  caloric,  air  and 
water  upon  the  fibro-cartilaginous  texture. — It  reddens 
by  maceration. — Absence  of  the  perichondrium  upon 
most  of  the  fibro-cartilages.  317 

II.  Parts  common  to  the  Organization  of  the  Fibro- 
cartilaginous System,  320 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  FIBRO-CARTILAGINOUS  SYSTEM. 

I.  Physical  Properties, 

Elasticity  and  suppleness  united.  320 

II.  Properties  of  Texture. 

Extensibility. — It  is  quite  evident  in  it. — Contractility. — 
Difference  from  elasticity.  321 

III.  Vital  Properties. 

They  are  inconsiderable. — Influence  of  the  obscurity  of 
these  forces  upon  the  properties  of  the  fibro-cartilages.  322 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  FIBRO-CARTILAGINOUS  SYSTEM. 

I.  State  of  this  System  in  the  First  Age. 
Mode  of  development  of  the  three  classes. 


323 


454 


ANALYTICAL  TABLE 


I'AaE. 


1].  Slate  of  this  System  in  the  after  Ages. 

General  rig-idity  of  these  organs. — Consequences. — Ossifi- 
cation of  the  fibro-cartilages  rare. 


325 


MUSCULAR  SYSTEM  OF  ANIMAL  LIFE, 


Difference  between  the  muscles  of  the  two  lives. — Ob- 
servations upon  those  of  animal  life.  327 


ARTICLE  FIRST. 

OF  THE  FORMS  OF  THE  MUSCULAR  SYSTEM  OF  ANIMAL  LIFE. 

Division  of  these  muscles  into  long,  broad  and  short.  327 

I.  Forms  of  the  Long  Muscles. 

Place  which  they  occupy. — Their  division. — Their  sep- 
aration and  reunion. — Peculiar  forms  of  the  long  mus- 
cles of  the  spine.  328 

II.  Forms  of  the  Broad  Muscles. 

Where  they  are  situated. — Thickness. — Peculiar  forms 
of  the  broad  pectoral  muscles.  330 

III.  Forms  of  the  Short  Muscles. 

Where  they  are  found. — Their  arrangement. — Remarks 
upon  the  three  species  of  muscles.  331 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  MUSCULAR  SYSTEM  OF  ANIMAL  LIFE. 

I.  Texture  peculiar  to  this  Organization. 

Arrangement  of  this  texture  into  fasciculi. — Its  division 
into  fibres. — Length  of  the  fleshy  fibres  compared  with 


OF  CONTENTS. 


453 


PAGE 

that  of  the  muscle. — Their  direction. — Their  figure. — 
Their  softness. — Ease  of  their  rupture  in  the  dead 
body. — Difficulty  in  the  living.  332 

Composition  of  the  muscular  texture. — Action  of  the  air  in 
desiccation  and  putrefaction. — Action  of  cold  water. — 
Maceration  and  its  products. — Ease  with  which  the 
colouring  substance  is  removed. — Analogy  of  the  re- 
maining texture  with  the  fibrin  of  the  blood. — Relation 
of  the  forces  with  this  texture. — Action  of  boiling 
water. — Some  peculiar  phenomena  of  common  boiled 
flesh. — Roasting  of  the  fleshy  texture. — Singular  affinity 
of  the  digestive  juices  to  this  sort  of  texture. — General 
■ observations. — Influence  of  sex  and  the  genital  organs 
upon  the  fleshy  texture.  336. 

II.  Paris  common  to  the  Organization  of  this  System. 

Cellular  texture. — Manner  in  which  it  envelops  the  fibres. 

— Its  uses  for  muscular  motion. — Experiment. — Fatty 
muscles.  343 

Blood  vessels. — Arteries. — Of  the  blood  of  the  muscles. — 

Of  their  colour. — Free  and  combined  state  of  the  colour- 
ing substance. — Veins — Remarks  upon  the  injection  of 
them.  346 

JVerves. — There  are  hardlj'  any  but  those  of  animal  life. — 
Their  difference  in  the  extensors  and  the  flexors. — 
Manner  in  which  the  nerves  penetrate  the  muscles.  348 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  MUSCULAR  SYSTEM  OF  ANIMAL  LIFE. 

I.  Properties  of  Texture.  Extensibility. 

This  property  is  continually  in  action. — It  is  in  proportion 
to  the  length  of  the  fibres. — Its  exercise  in  diseases.  350 
Contractility  of  texture. — Phenomena  of  the  antagonists. — 
Distinction  in  these  phenomena  of  that  which  belongs 
to  the  vital  properties  from  that  which  belongs  to 
those  ot  texture. — Of  the  contractility  of  texture  in 
diseases. — Extent  and  quickness  of  the  contractions. — 
They  continue  after  death. — Essential  differences  be- 
tween the  contractility  of  texture  and  horny  hardening. 
Their  parallel.  352 


456 


ANALYTICAL  TABLE 


II.  Vital  Proper  lies. 


PAGE 


Properties  of  animal  life. — Sensibility. — Most  of  the  ordi- 
nary agents  do  not  develop  it. — It  is  put  into  action  by 
repeated  contractions. — Of  the  sensation  of  lassitude. — 
Sensibility  of  the  muscles  in  their  affections.  359 

Animal  Contractility. — It  should  be  considered  in  three  re- 
lations. 361 

Animal  contractility  considered  in  the  brain. — The  principle 
of  this  property  exists  in  this  organ. — Proofs  drawn 
from  observation. — Proofs  derived  from  diseases. — 
Proofs  borrowed  from  experiments  upon  animals. — 
Cases  in  which  the  brain  is  foreign  to  the  muscles.  362 
Animal  contractility  considered  in  the  nerves. — Influence  of 
the  spinal  marrow  upon  this  property. — Observations 
and  experiments. — Influence  of  the  nerves. — Observa- 
tions and  experiments. — All  the  nerves  do  not  transmit 
equally  the  different  irradiations  of  the  brain. — Direc- 
tion of  the  propagation  of  the  nervous  influence.  367 

Anhnal  contractility  considered  in  the  muscles. — Necessary 
conditions  in  the  muscle  for  it  to  contract. — Obstacles 
to  contraction. — Various  experiments.  374 

Causes  which  bring  into  action  animal  contractility. — Divi- 
sion of  these  causes. — Of  the  will.— Of  the  involuntary 
causes. — Direct  excitement. — Sympathetic  excitement. 

— Influence  of  the  passions. — Remarks  upon  the  mo- 
tion of  the  foetus.  374 

Duration  of  the  animal  contractility  after  death. — Various 
experiments. — Consequences  relative  to  respiration. — 
Variety  of  the  duration  of  this  property. — How  it  is 
extinguished.  379 

Organic  Properties. — Organic  sensibility  and  insensible 
organic  contractility. — Sensible  organic  contractility. — 
Various  experiments  upon  this  last  property. — Phenom- 
ena of  irritations. — In  order  to  study  this  contractility 
the  animal  contractility  must  be  destroyed. — How  this 
is  done. — Various  modes  of  contraction.  382 

Sympathies. — The  animal  sensibility  is  the  property  espe- 
cially brought  into  action  by  them. — General  Remarks. 

— Sympathies  of  animal  sensibility. — The  organic  pro- 
perties are  rarely  brought  into  action.  386 

Characters  of  the  vital  properties. — Difierent  remarks  upon 
these  characters.  388 


OF  CONTENTS. 


457 


ARTICLE  FOURTH. 

PHEN'OMEJJA  or  THE  ACTION  OF  THE  MUSCULAR  SYSTEM  OF  ANIMAL 

LIFE. 

I.  Force  of  the  Muscular  Contraction. 

PAGE 

Difference  according  as  it  is  pat  into  aclion  by  stimuli  or 
by  the  cerebral  influence. — Experiments. — Influence  of 
muscular  organization  upon  contraction. — The  laws  of 
nature  ihe  reverse  of  those  of  mechanics  in  the  pro- 
duction of  motions. — Multiplication  of  forces. — Uncer- 
tainty of  calculations  upon  this  point.  390 

II.  Quickness  of  the  Contractions. 

Varieties  according  as  the  contractions  are,  1st,  from 
stimuli;  2d,  from  nervous  action. — Different  degrees  of 
quickness  in  different  individuals. — Influence  of  habit 
upon  this  degree.  396 

HI.  Duration  of  the  Contractions.  397 

IV.  Slate  of  the  Muscles  in  Contraction. 

Different  phenomena  which  they  then  experience. — Es-' 
sential  remark  upon  the  different  modes  of  contraction.  398 

V.  Motions  imparled  by  the  Muscles. 

Simple  Motions. — 1st.  In  the  muscles  with  a straight  di- 
rection.— How  we  determine  the  uses  of  these  muscles. 

— 2d.  In  the  muscles  with  a reflected  direction. — 3d. 

In  those  with  a circular  direction.  400 

Compound  Motions. — Almost  every  motion  is  compound. — 
How. — Different  examples  of  compound  motions. — 
Antagonist  muscles.  403 

VI.  Phenomena  of  the  Relaxation  of  the  Muscles. 

They  are  opposite  to  the  preceding. 

VOL.  m.  58 


406 


458 


ANALYTICAL  TABLE  OF  CONTENTS. 


ARTICLE  FIFTH. 

I>EVELOPMENT  OF  THE  MUSCULAR  SYSTEM  OF  ANIMAL  LIFE. 

i.  Stale  of  this  System  in  the  Foetus. 

PAGE 

It  contains  but  little  blood. — Slight  contractility  at  this 
age. — Influence  upon  these  phenomena,  of  the  blood 
which  then  penetrates  the  muscles. — These  organs  are 
then  slender  and  weak.  407 

IT.  Stale  of  this  System  during  Growth. 

Sudden  effect  of  the  red  blood  which  penetrates  the  mus- 
cles, and  of  the  other  irritations  which  are  connected 
with  it. — Colour  of  the  Muscles. — Period  of  the  bright- 
est colour. — Varieties  of  the  action  of  reagents  on  the 
fleshy  texture  of  young  animals.  410 

III.  Slate  of  this  System  after  Growth. 

The  thickness  constantly  increases. — The  external  forms 
are  more  evident. — Colour  in  the  adult. — Innumerable 
variety.  413 

IV.  State  of  this  System  in  Old  Age. 

Increase  of  density. — Diminution  of  cohesion. — Phenom- 
ena of  the  vacillation  of  the  muscles. — Atrophous  mus- 
cles. 416 

V.  State  of  the  System  at  Death. 

Relaxation  or  stiffness  of  the  muscles.  419 


END  OF  CONTENTS  TO  VOL.  II. 


VOLUME  THIRD. 


MUSCULAR  SYSTEM  OF  ORGANIC  LIFE. 


GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

FORMS  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC  LIFE. 

PAGE 

Curved  direction  of  the  fibres. — They  do  not  arise  from 
the  fibrous  system. — Varieties  of  the  muscular  forms, 
according  to  the  organs.  4 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC  LIFE. 

General  difierence  of  organization  from  the  preceding 
muscles.  5 

I.  Peculiar  Texture. 

General  arrangement  of  the  muscular  fibre. — Analogy 
with  the  preceding  and  difference.  6 

II.  Common  Parts. 

Cellular  Texture. — Blood  vessels. — Nerves  of  the  gan- 
glions and  of  the  brain. — Proportion  of  each  class. 


8 


460 


ANALYTICAL  TABLE 


ARTICLE  THIRD. 


PROPERTIES  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC  LIFE. 


I.  Properties  of  Texture. 


PAGE 

Extensibility. — Particular  character  of  this  property  in 
the  organic  muscles. — In  aneurisms  of  the  heart  and  in 
pregnancy,  it  is  not  the  extensibility  that  is  brought  into 
action. — Remarks  upon  this  subject.  10 

Contractility. — It  is  in  proportion  to  extensibility. — The 
substances  contained  in  the  hollow  muscles  are  their 
antagonists. — Remarks.  14 


II.  Vital  Properties. 


Sensibility. — Of  the  lassitude  of  the  organic  muscles. — 
Remarks  upon  hunger. 

Animal  Contractility. — It  is  nothing  in  these,  muscles. — 
Different  experiments. — Observations. — Of  the  muscles 
in  part  voluntary  and  in  part  organic. — Experiments. — 
Remarks  upon  the  bladder,  rectum,  &c. — Absence  of 
the  nervous  influence  upon  the  organic  muscles. 

Organic  Properties. — General  Rpmarks. 

Of  sensible  organic  contractility  considered  under  the  relation 
of  the  stimuli. 

Natural  stimuli. — Different  observations. — Remarks  upon 
the  fluids  and  solids. — Influence  of  the  quality  and 
quantity  of  the  fluids  upon  the  hollow  muscles. 

Artificial  stimuli. Action  of  these  stimuli. — Different 

modes  of  action. — Limits  of  the  horny  hardening  and 
vital  contraction. 

Of  sensible  organic  contractility,  considered  in  relation  to 
the  organs. 

First  variety.  Diversity  of  the  muscular  texture. — Each 
muscle  is  particularly  in  relation  with  some  determin- 
ate substance. — Application  of  this  principle  to  the 
natural  am!  foreign  fluids. 

Second  variety.  Age. — Vivacity  of  the  contractility  in  in- 
fancy.— Consequences. — Opposite  phenomenon  in  old 

age- 

Tlmrl  Variety.  Temperament. — Difference  of  individuals 
in  regard  to  organic  muscular  force. — This  force  is  not 
always  in  relation  to  the  animal  muscular  force. — It 
cannot  be  increased  like  it  by  habit. 


15 


17 

24 


25 


ib. 


28 


31 


ib. 


33 


34 


OF  CONTENTS. 


461 


I’AGE 


Fourth  Variety.  Sex.  35 

Fifth  Variety.  Season  and  climate.  36 

Sensible  organic  contractility  considered  in  relation  to  the  ac- 
tion of  stimulants  upon  the  organs. — The  constant  exist- 
ence of  an  intermediate  organ  for  this  action. — Nature 
of  this  intermediate  organ.  ib. 

Sensible  organic  contractility  considered  in  relation  to  its  du- 
ration after  death. — Ditference  of  this  duration  according 
to  the  kind  of  death. — Remarks.  38 

Sympathies. — Sympathies  of  the  heart. — S3'mpathies  of 
the  stomach. — Remarks  upon  bilious  vomitings. — Gene- 
ral observations. — Sympathies  of  the  intestines,  the 
bladder,  &c.  40 

Character  of  the  vital  properties. — Vital  energy  very  con- 
siderable in  this  system. — Its  affections  act  upon  its 
predominant  vital  force. — The  infrequency  of  the  af- 
fections which  suppose  a derangement  of  the  organic 
properties.  44 


ARTICLE  FOURTH. 

PHENOMENA  OF  THE  ACTION  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC 


LIFE. 

I.  Force  of  Contractions. 

Difference  from  the  force  of  contraction  of  the  preceding 
system. — It  is  greater  in  the  vital  phenomena  than  in 
experiments. — Inaccuracy  of  calculations.  46 

II.  Quickness  of  the  Contractions. 

In  experiments. — During  life. — Comparison  with  the 
quickness  of  the  preceding  muscles.  49 

HI.  Duration  of  the  Contractions.  50 

IV.  State  of  the  Muscles  in  Contraction. 

Difference  in  this  respect  between  the  heart  and  the  gastric 
muscles.  ib. 

V.  Motions  imparted  by  the  Organic  Muscles.  51 


VI.  Phenomena  of  the  Relaxation  of  the  Organic  Muscles. 

Differences  of  this  relaxation  from  the  active  dilatation  of 
the  muscles. — Proofs  of  the  phenomena  of  this  dilata- 
tion. 52 


462 


ANALYTICAL  TABLE 


ARTICLE  FIFTH. 


DEVELOPMENT  OF  THE  MUSCULAR  SYSTEM  OF  ORGANIC  LIFE. 


I.  Stale  of  this  System  in  the  Fafns. 


PAGE 


Predominance  of  the  heart. — State  of  the  other  muscles. 
— Weakness  of  the  organic  contractility  at  this  age. 


55 


II.  State  of  the  Organic  Muscular  System  during  Growth. 

General  increase  of  action  at  birth. — Of  the  growth  in 
thickness  and  of  that  in  length. — Their  differences.  58 


III.  Stale  of  the  OrganicMuscular  System  after  Growth.  61 

IV.  State  of  the  Organic  Muscular  System  in  Old  Age. 

This  s}'stem  outlives,  if  we  may  so  say,  the  preceding. — 
Phenomenon  resulting  from  its  weakness.  62 


MUCOUS  SYSTEM. 

ARTICLE  FIRST. 

OF  TitE  DIVISIONS  AND  FORMS  OF  THE  MUCOUS  SYSTEM. 

1.  Of  the  two  general  Mucous  Membranes,  the  Gastro-pul- 
monary  and  the  Genilo-urinary. 

Difference  of  these  two  membranes. — Their  relation.  66 

II.  Adhering  Surface  of  the  Mucous  Membranes. 

Its  relations. — It  is  everywhere  subjacent  to  the  muscles. 

— Sub-mucous  texture. — Experiments.  69 

III.  Free  surface  of  the  Mucous  Membranes. 

Of  the  folds  it  exhibits. — 1st.  Of  those  which  comprehend 
all  the  membranes. — 2d.  Of  those  which  are  permanent 


OF  CONTENTS. 


463 


PAGE 

upon  the  raucous  surface. — 3d.  Of  those  which  are 
owing  to  a state  of  vacuity  of  the  hollow  organs. — Dif- 
ferent experiments. — The  extent  of  the  mucous  sur- 
faces is  always  nearly  the  same,  whatever  may  be  the 
state  of  their  organs. — Relation  of  their  free  surface 
with  external  bodies. — Their  sensibility  is  accommo- 
dated to  this  relation. — The  term  foreign  body  is  mere- 
ly comparative.  70 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  MUCOUS  SYSTEM. 

I.  T'exture  peculiar  to  this  Organization. 

What  it  presents  for  consideration. 

Mucous  Corion. — Its  variable  thickness. — Mucous  nature 
of  the  membrane  of  the  ear. — Pathological  conse- 
quences.— Softness  of  the  mucous  texture. — Action  of 
the  air,  water,  caloric,  the  acids  and  the  digestive  juices 
upon  the  mucous  texture.  76 

Mucous  papilla. — Their  varieties  of  form. — Their  nervous 
nature. — Proofs  of  this  nervous  nature. — Their  influ- 
ence upon  the  sensibility  of  the  mucous  organs,  83 

II.  Common  Parts. 

Of  the  mucous  glands  and  the  fluids  •which  they  secrete. — 
Situation. — Forms. — Size. — Texture.  86 

Mucous  fluids. — Physical  properties. — Action  of  different 
agents  upon  them.— Their  functions. — Parts  in  which 
they  are  most  abundant  and  those  in  which  they  are 
less  so. — Susceptibility  of  being  increased  by  any  irri- 
tation made  upon  their  excretories. — Consequences. — 
Remarks  upon  the  excitement  of  the  mucous  surfaces 
in  diseases. — Uses  of  the  mucous  membranes  in  rela- 
tion to  the  habitual  evacuation  of  their  fluids. — Gene- 
ral remarks  upon  the  secreted  fluids. — Singular  sensa- 
tion arising  from  the  continuance  of  the  mucous  fluids 
upon  their  respective  surfaces.  88 

Blood  vessels. •~-TheiT  varieties  of  proportion. — Their 
superficial  position. — Consequence. — Redness  of  the 
mucous  system. — It  often  loses  it. — Experiments  upon 
the  state  of  the  mucous  vessels  in  the  fulness  and  vacui- 


464 


ANALYTICAL  TABLE 


PAGE 

ty  of  their  hollow  organs. — Other  esperimenls  upon 
the  influence  of  the  gases  upon  the  colour  of  the  mu- 
cous system. — Causes  of  its  redness. — Colouring  sub- 
stance combined  and  free.  96 

Exhalants. — Is  there  exhalation  upon  the  mucous  system? 

— Pulmonary  exhalation. — A great  part  of  the  pulmo- 
nary perspiration  arises  from  the  solution  of  the  mu- 
cous juices. — Other  mucous  exhalations. — Hemorrhages.  105 
Msorbenis. — Proofs  of  the  mucous  absorption. — Irregu- 
larity of  this  absorption. — Cause  of  this  irregularit}'.  107 
JYerves. — Those  of  the  brain. — Those  of  the  ganglions. — 
Their  respective  distribution  upon  this  system.  108 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  MUCOUS  SYSTEM. 

J.  Properties  of  Texture, 

They  are  less  than  they  at  first  seem  to  be. — They  are 
however  real. — Their  variety. — The  mucous  ducts  are 
not  obliterated  by  the  contractility  of  texture  when 
they  are  empty.  109 

II.  Vital  properties. 

Properties  of  animal  life. — Acute  sensibility  of  the  mucous 
system. — Influence  of  habit  upon  this  property. — Con- 
sequences of  this  remark. — Mucous  sensibility  in  inflam- 
mations. Ill 

Properties  of  organic  life. — Organic  sensibility  and  insen- 
sible contractility  are  very  evident  here. — Why. — Con- 
sequences as  it  respects  diseases. — Varieties  of  these 
properties. — Species  of  sensible  organic  contractility  in 


the  mucous  texture.  114 

Sympathies. — How  we  shall  divide  them.  117 

Active  Sympathies. — Example  of  these  sympathies  for 
each  vital  property.  1 18 

Passive  Sympathies. — The  predominant  ones  are  those  of 
insensible  organic  contractility. — Why.  120 

Character  of  the  vital  properties. — Vital  activity  of  this  sys- 
tem.— Its  varieties. — Consequences  as  it  regards  dis- 
eases.— Remarks  upon  the  stomachic  sympathies.  123 


OF  CONTENTS. 


465 


ARTICLE  FOURTH. 

DEVELOPMENT  OP  THE  MUCOUS  SYSTEM. 

I.  Stale  of  the  Mucous  System  in  the  First  Age. 

PAGE 

It  follows  the  state  of  the  organs  to  which  it  belongs. — 
Delicacy  of  the  papillae. — The  mucous  redness  is  then 
deeper. — Sudden  change  at  birth. — Why. — Phenome- 
non of  puberty.  125 

II.  State  of  the  Mucous  System  in  the  After  Ages, 

Its  phenomena  in  the  adult. — Its  phenomena  in  old  age.  129 


SEROUS  SYSTEM.  ' 

GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

OF  THE  EXTENT,  FORMS  AND  FLUIDS  OF  THE  SEROUS  SYSTEM. 

General  arrangement  of  its  membranes. — Of  the  serous 
surface  considered  in  general. — Every  serous  mem- 
brane is  a sac  without  an  opening.  131 

I.  Free  Surface  of  the  Serous  Membranes. 

It  is  smooth  and  polished. — This  attribute  is  foreign  to 
compression.  This  surface  insulates  the  organs  to 
which  the  serous  surfaces  belong.- — Its  influence  upon 
the  motion  of  these  organs. — Adhesions  of  the  serous 
surfaces. — Their  division.  134 

II.  Adhering  Surface  of  the  Serous  System. 

Means  of  union. — The  serous  membranes  often  change  re- 
lations with  their  organs. — This  is  owing  to  the  laxity 
of  the  adhesions. — Adhesions  more  close.  140 

VOL.  iir.  S9 


466 


ANALYTICAL  TABLE 


I 


III.  Serous  Fluids. 


PAGE 

Trheir  quantity. — Varieties  of  this  quantity. — Experi- 
ments.— Morbid  varieties. — Nature  of  these  fluids.  142 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  SEROUS  SYSTEM. 

The  serous  membranes  have  but  one  layer. — Its  colour. 

— Its  thickness.  144 

I.  Cellular  nature  of  the  Serous  Texture. 

Proofs  of  this  cellular  nature. — Experiments  by  macera- 
tion, ebullition,  desiccation,  stewing'  and  putrefaction. — 
Diflerences  between  the  cellular  and  serous  textures.  145 

II.  Parts  common  to  the  organization  of  the  Serous  System. 

Exhalants. — Various  proofs  of  serous  exhalation.  149 

Ahsorbents, — Proofs  of  serous  absorption. — Experiments. 

— Mode  of  origin  of  the  absorbents.  150 

Blood  vessels. — The  serous  membranes  have  but  very  few 
of  them. — Those  which  are  subjacent  do  not  belong  to 
them. — Proofs.  151 

III.  Varieties  of  Organization  of  the  Serous  System. 

Different  examples  of  these  varieties. — Consequences  in 
regard  to  diseases. — Remarks  upon  the  pericardium. — 
Common  characters.  1 53 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  SEROUS  SYSTEM. 

I.  Properties  of  Texture. 

Extensibility. — It  is  less  than  it  at  first  seems  to  be. — Vv^hy. 
— Use  of  the  folds  of  the  serous  membranes. — Of  their 


OF  CONTENTS. 


467 


PAGE 

displacement. — Pain  from  these  displacements  in  inflam- 
mation. 155 

Contractility. — Less  than  it  appears  to  be. — It  is  however 
real.  156 

II.  Vital  Properties. 

They  enjoy  but  little  animal  sensibility. — Why. — Experi- 
ments.— The  organic  properties  are  very  sensible. — 
Consequences.  157 

Sympathies. — Various  examples. — Remarks  upon  sympa- 
thetic exhalations. — Remark  upon  the  serum  of  dead 
bodies.  158 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  SEROUS  SYSTEM. 

I.  Stale  of  this  System  in  the  First  Age. 

Extreme  tenuity  of  the  surfaces. — Quantity  of  the  fluids. 

— Quality. — Changes  at  birth. — Experiments.  161 

II.  Slate  of  the  Serous  System  in  the  After  Ages. 

The  serous  surfaces  obey  the  laws  of  their  respective 
organs. — Increased  density  in  old  age. — Ossification 
rare.  162 

III.  Preternatural  Development  of  the  Serous  System, 
Various  observations.  164 


SYNOVIAL  SYSTEM. 


Points  of  resemblance  between  this  system  and  the  pre- 
ceding.— Its  division.  165 


468 


ANALYTICAL  TABLE 


ARTICLE  FIRST. 

ARTICULAR  SYNOVIAL  SYSTEM. 

I.  How  the  Synovia  is  separated  from  the  mass  of  blood. 

1‘AGE. 

There  are  three  ways  in  which  fluids  may  be  separated 
from  the  blood. 

Is  the  Synovia  transmitted  by  secretion  to  the  articular  sur- 
faces ? — Negative  proofs. — Of  the  pretended  synovial 
glands. — Experiments. 

Is  the  Synovia  transmitted  by  transudation  to  the  articular  sur- 
faces ? — Negative  proofs. — Another  opinion. 

Is  the  Synovia  transmitted  by  exhalation  to  the  articular  sur- 
faces ? — Positive  proofs. — Analogy  between  the  ex- 
haled fluids  and  the  synovia. — Consequences.  167 

II.  Remarks  upon  the  Synovia. 

Its  quantity. — It  varies  a little. — Rare  alterations  of  this 
fluid. — Its  difference  from  the  serous  fluids.  173 

III.  Of  the  Synovial  Membranes. 

Forms.— They  represent  sacs  without  an  opening. — Dif- 
ference from  the  fibrous  capsules. — These  capsules 
are  wanting  in  the  greatest  number  of  articulations. — 
Experiments. — Proofs  of  the  synovial  membrane  where 


it  adheres.  175 

Organization. — Analogy  with  the  serous  surfaces. — Struc- 
ture of  the  pretended  synovial  glands.  180 

Properties. — Properties  of  texture. — Vital  properties. — 
Experiments. — The  synovial  system  is  foreign  to  most 
diseases.  182 

Functions. — They  are  foreign  to  the  soliditj^  of  the  articu- 
lation.— They  have  relation  only  to  the  synovia.  183 

Natural  Development. — State  of  the  synovial  membrane  in 
infancy,  adult  and  old  age.  184 

Preternatural  Development. — Remarks  upon  this  develop- 
ment. 185 


ARTICLE  SECOND. 

SYNOVIAL  SYSTEM  OF  THE  TENDONS. 

It  is  often  confounded  with  the  preceding.  186 

Forms;  relations;  synovial  fluid. — Forms  of  sacs  without 
an  opening. — Varieties  of  these  forms. — Smooth  and 


OF  CONTENTS. 


469 


PAGE 

adhering  surface. — Relation  with  the  tendon. — Preter- 
natural increase  of  the  fluid.  186 

Organization^  properties,  development. — Their  phenomena 
are  analogous  to  those  of  the  preceding  system. — Re- 
marks upon  the  affections  of  this  kind  of  synovial  mem- 
branes. 189 


GLANDULAR  SYSTEM. 


General  observations. — What  a gland  is. 


193 


ARTICLE  FIRST. 

SITUATION,  FORMS,  DIVISION,  &C.  OF  THE  GLANDULAR  SYSTEM. 

Sub-cutaneous  and  deep  position. — Relation  of  the  position 
of  the  glands  with  their  excretion. — Varieties  of  the 
glandular  forms. — Distinction  of  these  varieties. — Ex- 
ternal surface  of  the  glands.  194 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  GLANDULAR  SYSTEM. 

1.  Texture  peculiar  to  the  Organization  of  this  System, 

The  fibrous  arrangement  is  foreign  to  the  glands. — There 
is  but  little  resistance  in  the  glandular  texture. — Triple 
arrangement  of  this  texture. — Uncertainty  of  the  re- 
searches upon  its  nature. — Diflerent  experiments  upon 
this  texture. — Desiccation. — Peculiar  effect  of  stew- 
ing.— Roasting. — Maceration. — Action  of  the  acids, 
gastric  juice,  &c.  1 98 

Of  the  excretories,  their  origin,  divisions,  4’C.  of  the  glandu- 
lar reservoirs. — Origin.— Course. — Division  of  the  glands 


470 


ANALYTICAL  TABLE 


PASE 

into  three  classes,  in  regard  to  the  termination  of  their 
excretopies. — Of  the  reservoirs. — What  supplies  their 
place  when  thej'  are  wanting. — Motion  of  the  fluids  in 
the  excretories.  204 

Size^  direction  and  termination  of  the  excretories. — All  the 
excretories  open  upon  the  mucous  or  cutaneous  sys- 
tems.— Observations  upon  the  intestinal  canal.  206 

Remarks  upon  the  secreted  fluids. — They  can  re-enter  the 
circulation. — Various  experiments  on  this  subject. — 
Consequences.  208 

Structure  of  the  excretories. — Internal  membrane. — Exter- 
nal texture.  213 

II.  Paris  common  to  the  Organization  of  the  Glandular 
System. 

Cellular  Texture. — Division  of  the  glands  into  two  classes, 
in  regard  to  this  texture. — Serum  and  fat  of  this  tex- 
ture.— Fatty  livers.  214 

Blood  vessels. — Different  ways  in  which  they  enter  the 
glands,  according  as  they  are  or  are  not  surrounded 
with  membranes. — ^Course  of  the  arteries  in  the  glands. 

— Veins. — Thejf  pour  their  blood  into  the  general  black 


blood. — Reflux  from  the  heart  to  the  glands.  216 

Of  the  blood  of  the  glands. — Division  of  the  glands  into 
three  classes,  as  it  regards  the  fluid  which  penetrates 
them. — Great  quantity  of  blood  contained  in  the  liver 
and  the  kidney. — Variety  as  it  respects  secretion.  219 
J\'et'ves. — Of  those  of  the  ganglions  and  of  the  cerebral 
ones. — Their  proportion. — How  they  enter  the  glands. 

— Secretion  is  independent  of  nervous  influence.  221 

E.vlialants  and  absorbents:  223 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  GLANDULAR  SYSTEM. 

1.  Properties  of  Texture, 

They  are  inconsiderable. — Proofs. — New  remarks  upon 
the  reflux  of  the  black  blood  in  the  glands.  224 

II.  Vital  Properties. 

Properties  of  animal  life. — Experiments  upon  animal  sen- 
sibility.—Varieties  of  the  results.  226 


OF  CONTENTS, 


471 


PAGE 

Properties  of  organic  life. — The  insensible  contractility 
and  the  corresponding  sensibility  are  the  predominant 
ones. — Their  influence  upon  secretion. — Varieties  of 
the  secreted  fluids. — Organic  affections  of  the  glands. — 
Remarks.  * 227 

Sympathies.  230 

Passive  sympathies. — Various  examples. — Sympathies  the 
causes  of  which  act  at  the  extremity  of  the  excreto- 
ries. — Influence  of  the  passive  sympathies  of  the  glands 
in  diseases. — Remark  upon  that  of  each  gland. 

Active  Sympathies. — Various  remarks. 

Characters  of  the  vital  properties.  235 

First  character. — Fife  peculiar  to  each  gland. — Proofs  of 
this  peculiar  life. — Of  its  influence  in  a state  of  health 
and  disease. 

Second  character. — Remission  of  the  glandular  life. — The 
glands  have  a species  of  sleep. — Various  examples.  238 
Third  character. — The  glandular  life  is  never  simultaneously 
raised  in  the  whole  system. — Application  of  this  remark 
to  the  digestive  order. — Advantage  of  the  artificial  ex- 
citement of  the  glands  in  diseases.  239 

Fourth  character. — Influence  of  climate  and  season  upon 
the  glandular  life. — The  sweat  and  many  secreted  fluids 
are  opposite  to  each  other  in  this  respect.  241 

Fifth  character.  — Influence  of  sex  upon  the  glandular 
life.  242 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  GLANDULAR  SYSTEM. 

I.  State  of  this  System  in  the  Fatus. 

The  glands  are  very  conspicuous  at  this  age. — Yet  the 
secretions  are  not  great.  243 

II.  State  of  this  System  during  Growth. 

Suddenly  increased  activity  at  birth. — Yet  it  is  not  the 
glandular  system  which  predominates  in  the  first  age. 

— Remarks  upon  its  diseases. — The  mucous  and  lachry- 
mal glands  are  the  most  frequently  in  action  in  infancy.  244 


472 


ANALYTICAL  TABLE 


III.  Slate  of  this  System  after  Growth. 

PAGE 

Period  of  puberty. — Its  influence  upon  the  glands. — In- 
fluence of  the  glands  of  digestion  at  the  adult  age.  247 

IV.  Stale  of  this  System  in  old  -Mge. 

Of  the  change  in  the  texture  of  the  glands  from  the 
effect  of  age. — Many  glands  still  secrete  much  fluid  in 
old  age. — Relation  of  this  phenomenon  with  nutrition.  249 


DERMOID  SYSTEM. 

GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

FORMS  OF  THE  DERMOID  SYSTEM. 

I.  External  Surface  of  the  Dermoid  System. 

Various  folds  of  this  surface. — Their  different  nature.  254 

II.  Internal  Surface  of  the  Dermoid  System. 

Its  relations. — Absence  of  the  fleshy  pannicle  in  man. — 
Consequences.  256 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  DERMOID  SYSTEM. 

I.  Texture  peculiar  to  the  Organization. 

Chorion. — Its  thickness  in  the  different  regions. — Its  struc- 
ture.— Method  of  seeing  it. — Variety  of  this  structure 
according  to  the  regions. — Small  spaces  of  the  chorion. 
— Fibres. — Their  nature. — It  approximates  that  of  the 


OF  CONTENTS. 


473 


PAGE 

fibrous  texture. — Yet  it  differs  from  it. — The  chorion  is 
foreign  to  the  functions  of  the  skin  relative  to  animal 
and  organic  life.  258 

Of  the  reticular  body. — Idea  that  has  been  formed  of  it. — 
What  it  is. — Vascular  net-work. — Colouring  substance. 

— Analogy  among  the  diversity  of  races. — How  this 
diversity  should  be  considered. — Of  the  cases  in  which 
the  blood  enters  the  reticular  body. — Singular  property 
of  the  vessels  of  the  face  of  receiving  more  than  the 
others. — Cause  of  this  phenomenon. — Triple  means  of 
expression  of  the  passions. — Relation  between  the 
tendency  of  the  facial  capillary  system  to  receive  blood 
and  diseases. — Double  state  of  the  reticular  body. — 


Phenomena  at  the  instant  of  death. — Experiments.  266 

Papillce. — Situations. — The  cutaneous  prominences  must 
not  be  taken  for  them. — Experiments  to  prove  the  na- 
ture of  these  prominences. — Their  varieties. — Forms 
and  nervous  structure  of  the  papillas.  273 

Action  of  different  bodies  upon  the  dermoid  texture.  276 

Action  of  light. — Men  whiten  like  plants. — Examples.  ib. 

Action  of  caloric. — Effects  which  it  produces  on  the  skin 
during  life  according  to  its  different  degrees. — Effect  of 
cold. — General  remarks  upon  gangrene  and  antiseptics. 

— False  opinions  of  authors.  277 

Action  of  the  air. — Remarks  upon  the  influence  of  this 
fluid  upon  the  evaporation  of  the  transpiration. — It  is 
foreign  to  this  function  itself. — Desiccation  of  the  skin 
by  the  air. — Its  putrefaction.  282 


Action  of  -water. — General  uses  of  baths. — Their  use  is 
natural, — Maceration  of  the  skin. — Pulpy  state. — Stew- 
ing of  the  skin. — Mode  of  horny  hardening. — ^Vesicles 
that  arise  the  instant  it  takes  place. — Other  phenomena 
of  stewing.  285 

Action  of  the  acicfc,  alkalies,  and  other  substances. — Various 
experiments  with  reagents. — Remarks.  290 


II.  Parts  common  to  the  Organization  of  the  Dermoid 
System, 


Cellular  texture. — Manner  in  which  it  is  distributed. — Re- 
marks upon  biles. — Sometimes  it  is  wholly  destroyed. — 
Appearance  which  the  skin  then  has. — Remarks  upon 
lewcophlegmasia.  291 

Blood  vessels. — Manner  in  which  they  are  distributed. — 
Dilatation  of  the  veins  in  some  cases.  293 

Nerves. — Mode  of  their  distribution.  294 

TOL.  III.  60 


474 


ANALYTICAL  TABLE 


PAGE 

Ahsorhents. — Proofs  of  cutaneous  absorption. — Absorption 
of  virus. — Table  of  this  absorption. — Varieties  it  ex- 
periences.— Absorption  of  medicines. — Experiments. — 
Character  of  irregularity  of  the  cutaneous  absorptions. 

— To  what  this  character  is  owing. — Influence  of  weak- 
ness on  this  absorption.  294 

Exhalants.—Modie  of  distribution. — Cutaneous  exhalations. 

— Uncertainty  of  calculations  upon  this  point. — Rela- 
tion of  this  exhalation  with  the  secretions. — Relation 
with  the  pulmonary  exhalation. — Experiment  upon  this 
last  exhalation. — Remarks  upon  the  causes  of  many 
coughs. — Defect  of  evaporation  of  the  fluid  deposited 
upon  the  bronchia. — The  cutaneous  exhalants  vary. — 

Are  they  under  the  nervous  influence? — This  does  not 
appear  probable.  299 

Sehace,aus  Glands. — Oily  fluid  of  the  skin. — Its  quantity. — 

Its  varieties. — Its  sources. — We  have  but  few  data  as  it 
regards  the  sebaceous  glands.  305 


ARTICLE  THIRD. 


PKOPERTIES  OF  THE  DERMOID  SYSTEM. 


I.  Properties  of  Texture. 


They  are  very  evident. — They  are  often  less  than  they 
seem  to  be. — Phenomena  of  extensibility  and  contrac- 
tility. 


308 


II.  Vital  Properties. 

Properties  of  animal  life. — Sensibility. — Of  the  feeling. — 

Of  the  touch. — Its  characters. — Its  differences  from  the 
other  senses.— Seat  of  cutaneous  sensibility.— The  mode. 

Pain  peculiar  to  the  skin. — Influence  of  habit  upon 

this  sensibility. — Various  reflections. — Diminution  of 
the  cutaneous  sensibility.  . 

Properties  of  organic  life. — They  are  especially  organic 
sensibility  and  insensible  contractility. — Phenomena 
over  which  they  preside. — Division  ot  cutaneous  dis- 
eases.— Excitants  of  the  cutaneous  organic  sensibility.—* 
Sensible  organic  contractility  is  but  slightly  apparent.  318 

Sympathies. — Passive  Sympathies. — Different  examples  and 
remarks  upon  the  sympathies  of  heat. — General  re- 


OF  CONTENTS. 


475 


PAGE 


marks  upon  the  sensations  of  heat  and  cold. — Influence 
of  sympathies  upon  the  sweat.  322 

Active  Sympathies. — These  sympathies  are  relative  to  each 
of  the  classes  of  diseases  pointed  out  above. — Various 
examples. — General  remarks.  326 

Characters  of  the  vital  properties. — First  character. — The 
cutaneous  life  varies  in  each  region. — Varieties  of  animal 
spnsibility. — Varieties  in  the  organic  properties.  331 

Second  character. — Intermission  in  one  relation.^  continuity  in 
another. — The  peculiar  life  of  the  skin  is  intermittent 
as  it  respects  the  functions  of  relation. — Its  continuity 
as  it  respects  its  organic  functions.  332 

Third  character. — Influence  of  sex.  333 

Fourth  character. — Influence  of  temperament.  334 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  DERMOID  SYSTEM. 

I.  Stale  of  this  System  in  the  Foetus, 

A gluey  covering  in  the  first  periods. — Absence  of  certain 
wrinkles  in  the  fostus. — Laxity  of  adhesion. — State  of 
the  vital  properties  of  the  skin  of  the  foetus. — Its  func- 
tions at  this  age.  335 

II.  State  of  this  System  during  Growth. 

Sudden  revolution  at  birth. — Entrance  of  the  red  blood 
into  the  skin. — Consequences. — State  of  the  cutaneous 

t vital  forces  in  infancy. — State  of  the  cutaneous  texture.  337 

III.  State  of  the  Dermoid  System  after  Growth. 

Increasing  proportion  of  the  fibrous  substance,  and  de- 
creasing proportion  of  the  gelatinous. — Remark  upon 
the  diseases  and  affections  of  the  skin.  341 

IV.  State  of  the  Dermoid  System  in  Old  Age. 

State  of  the  cutaneous  texture. — Phenomena  which  arise 
from  it. — State  of  the  vital  forces. — State  of  the  func- 
tions. 34 1 


476 


ANALYTICAL  TABLE 


EPIDERMOID  SYSTEM. 

PA«E 

General  Observations. — Division.  349 


ARTICLE  FIRST. 

OF  THE  EXTERNAL  EPIDERMIS. 

I.  Forms,  Relations  with  the  Dermis,  i^c. 

Wrinkles. — Pores. — Adhesion  to  the  skin. — Means  of  de- 
stroying this  adhesion. — Arrangement.  350 

II.  Organization,  Composition,  <^c. 

Uniform  thickness  in  most  parts. — Remarkable  thickness 
on  the  foot  and  the  hand. — Consequences  of  this  thick- 
ness.— Experiments  upon  the  colour  of  negroes. — Epi- 
dermoid texture. — Its  peculiar  nature. — Action  of  the 
air,  water,  caloric,  the  acids,  the  alkalies,  &c.  upon  the 
epidermoid  texture.  353 

III.  Properties. 

Extensibility. — The  animal  properties  are  foreign  to  the 
epidermis. — It  appears  to  be  destitute  also  of  organic 
properties. — Continual  destruction  of  the  epidermis. — 

Its  reproduction  when  it  is  removed.  360 

IV.  Development. 

State  of  the  epidermis  in  the  foetus,  the  adult  and  the  old 
person.  364 


ARTICLE  SECOND. 

INTERNAL  EPIDERMIS.  GENERAL  OBSERVATIONS  UPON  THIS  EPI- 
DERMIS. 

I.  Epidermis  of  the  origin  of  the  Mucous  Surfaces. 

It  is  very  distinct. — Proofs  of  its  existence. — Its  reproduc- 
tion.— Its  nature.  366 


OF  CONTENTS. 


477 


II.  Epidermis  of  the  deep  Surfaces. 

PAGE 

Uncertainty  of  its  existence. — Experiments. — Membranes 
, that  are  sometimes  thrown  off. — It  appears  that  it  is  not 
the  epidermis.  367 


ARTICLE  THIRD. 

OF  THE  NAILS. 

I.  Form.,  Extent,  Relations, 

Of  the  habit  of  cutting  the  nails. — Anterior,  middle  and 
posterior  portions  of  the  nail. — Superior  and  inferior 
surfaces. — Of  the  texture  which  supports  the  nail.  869 

II.  Organization,  Properties,  4/-c. 

Of  the  laminae  which  form  the  nails. — Of  their  arrange- 
ment.— Their  analogy  with  the  epidermis. — Obscurity 
of  the  vital  properties. — Facility  with  which  the  nails, 
epidermis,  &c.  are  coloured.  373 

Development. — State  of  the  nails  ia  the  foetus,  the  adult, 
and  the  old  person.  376 


PILOUS  SYSTEM, 


GENERAL  OBSERVATIONS. 


ARTICLE  FIRST. 

EXAMINATION  OF  THE  PILOUS  SYSTEM  IN  THE  DIFFERENT  REGIONS. 

I.  Pilous  System  of  the  Head. 

General  observations.  379 

OJ  the  Hair. — Its  length,  situation,  limits,  influence  on 
physiognomy,  variety  according  to  sex,  uses,  thickness. 


478 


ANALYTICAL  TABLE 


fundamental  colours,  shades,  and  influence  on  tempera- 


ment. 381 

Eyebrows. — Their  general  arrangement. — Their  motions.  386 
Eyelashes. — Their  form,  arrangement,  &c.  387 

Beard. — It  is  the  attribute  of  the  male. — Its  relations  with 
strength. — Of  our  habits  in  relation  to  the  beard.  388 

II.  Of  the  Pilous  System  of  the  Trunk. 

Its  varieties  according  to  the  regions.  390 


III.  Pilous  System  of  the  Extremities. 

Its  varieties. — It  is  wanting  on  the  palms  of  the  hands  and 
the  soles  of  the  feet.  ib. 


ARTICLE  SECOND. 

ORGANIZATION  OF  THE  PILOUS  SYSTEM. 

I.  Origin  of  the  Hairs. 

Of  the  membranous  canal  which  encloses  this  origin. — 
Relation  of  the  hair  with  this  canal. — Organization  of 
this. — Swelling  of  the  hair  and  its  origin. — Its  course 
to  the  exterior.  391 

II.  External  Covering  of  the  Hairs. 

Analogy  of  this  covering  with  the  epidermis. — Its  differ- 
ences.— Action  of  the  difierent  agents  upon  this  cover- 
ing.— Its  external  arrangement.  394 

III.  Internal  Substance  of  the  Hairs. 

We  are  ignorant  of  its  nature. — Capillaries  of  the  hairs  of 
the  head. — Their  colouring  substance. — The  internal 
substance  of  the  hairs  of  the  head  is  essentially  subject- 
ed to  the  influence  of  the  vital  phenomena. — Proof  of 
this  assertion. — This  distinguishes  it  from  the  external 
covering.  396 


OF  CONTENTS. 


479 


ARTICLE  THIRD. 

PROPERTIES  OF  THE  PILOUS  SYSTEM. 

PAGE 

It  undergoes  but  little  horny  hardening. — Of  curling. — 

The  properties  of  texture  slightly  marked.— The  ani- 
mal ones  are  nothing. — The  organic  are  a little  more 
evident.  401 


ARTICLE  FOURTH. 

DEVELOPMENT  OF  THE  PILOUS  SYSTEM. 

I.  Slate  of  this  System  in  the  First  Age. 

Of  the  down  of  the  foetus — The  growth  of  the  hairs  is 
then  the  reverse  of  that  of  the  other  parts. — Their 
growth  after  birth. — Their  colours  are  a little  deeper 
in  infancy.  403 

II.  Slate  of  the  Pilous  System  in  the  following  Ages, 

Revolution  at  puberty. — Of  the  hairs  which  then  appear. 

— There  are  but  few  changes  in  the  following  ages.  404 

III.  Stale  of  the  Pilous  System  in  Old  Age. 

Of  the  hairs  which  die  first. — Of  the  whiteness  which 
they  then  assume. — They  grow  in  this  state. — Why. — 

Do  they  grow  after  death. — General  differences  of  ani- 
mate and  inanimate  bodies  in  their  decay.  405 

IV.  Preternatural  Development.] 

Development  upon  the  mucous  surfaces,  upon  the  skin 
and  in  cysts.  408 


END  OF  THE  THIRD  AND  LAST  VOLUME. 


f 


I 

Bichat 

1822 
V.  3 


